Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/19/16

Area Forecast Discussion
National Weather Service Wilmington NC
933 PM EDT WED MAY 18 2016

.SYNOPSIS...
High pressure will build from the north overnight into Thursday.
A warm front will lift across the region Friday...bringing an
increasing chance of rain. A surface low and its attendant cold
front will sustain wet conditions Saturday into very early Sunday.
A drying trend is expected early next week with near to slightly
below normal temperatures.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
As of 933 PM Wednesday...No significant changes required with the
middle evening updates as mostly cloudy skies prevail with local
temperatures overnight very close to climatology for this time of
May. No drivers for significant PCPN tonight aside from MCV
perturbation showers west of I-95 after 2 AM. Low-level saturation
late tonight may materialize a patch or 2 of drizzle, but for most
locations, measurable rainfall is not likely. With low cloud
ceilings and nearly saturated low level air, temperature drops
will be slow to evolve, settling in the upper 50s to lower 60s
daybreak Thursday. A pocket of mist or fog cannot be ruled out
overnight as well given the very damp regime in place near the
surface.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
As of 3 PM Wednesday...High pressure centered over the Great
Lakes on Thursday morning pushes east over the mid-Atlantic states
by Friday morning as a system emerging from the deep south moves
northeast and up the coastal plain. This will bring increasing
chances of rain on Friday after minimal chances on Thursday. We
could see isolated thunder on Friday night as the low pressure
system and an associated deepening upper trough move over the
central Carolinas.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 3 PM Wednesday...Period begins with surface system exiting
to the north and 5h trough moving in from the west. Precip ongoing
Sat morning will come to an end during the afternoon as west to
northwest flow aloft advects in much drier air. PWATs drop from
near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival
of dry air combined with low level subsidence will bring an end to
the rainfall. Mid level trough lingers over the area for the
weekend, briefly becoming cutoff Sun into Mon. Some disagreement
between the latest GFS/ECMWF as to the placement of the 5h cutoff
but it will be close enough to ensure temps below climo, cloudy
skies, and possibility of isolated afternoon instability showers
Sun. Troughing will remain over or just off the east coast through
the end of the period, keeping unsettled weather close by.
However, precip chances should diminish quickly Mon as deep
northwest flow aloft develops. Temps a little below climo Mon
climb near climo Tue and above climo Wed as weak mid level ridge
starts to build over the southeast.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
As of 00Z...MVFR with brief improvement to VFR possible this
evening before widespread MVFR/IFR returns with areas of fog
possible overnight. Improvement to VFR on Thursday is expected
with increasing chances for showers throughout the day.

Though latest radar imagery remains fairly quiet this evening,
satellite imagery continues to show broken to overcast coverage of
low clouds allowing for widespread MVFR to prevail at the terminals.
Trends do indicate the potential for brief improvement to VFR over
the next few hours, before cloud coverage increases again overnight.
This along with developing areas of fog will create MVFR/IFR through
the early morning hours. Light and variable winds are expected.
After daybreak, expect conditions to improve to VFR with increasing
chances for showers into the afternoon hours. Northeasterly winds
around 5 kts in the morning will become east-northeasterly in the
afternoon around around 10 kts.

Extended Outlook...VFR Thur before convection and possible MVFR/IFR
return Fri through Sun.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 933 PM Wednesday...`Exercise Caution" headline is needed
for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly
mellower wind-speeds over the SC waters precludes this headline.
Caution headline valid until midnight tonight as wind trends ease
this evening, as a low offshore of Cape Lookout moves NE away from
the coast...thus a very brief cautionary period. Virtually no wave
energy with wave periods greater than 7 seconds exists right now
and all energy is tied to nearby winds...thus slightly steep and
bumpy this evening for only 3-5 ft seas. Dominant wave periods
will hold between 6-7 seconds overnight with little or no shower
activity.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 3 PM Wednesday...High pressure centered over the Great
Lakes on Thursday morning pushes east over the mid-Atlantic states
by Friday morning as a low pressure system emerging from the deep
south moves northeast and up the coastal plain. The pressure
gradient will not really tighten much until this system approaches
the Carolinas, so expect only a modest 10 to 15 kt wind range with
seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft
Friday night as winds gradually increase with the approach of the
low pressure system.

LONG TERM /SATURDAY THROUGH MONDAY/...
As of 3 PM Wednesday...Strong southerly flow at the start of the
period will become west to northwest later Sat and Sat night
following the passage of a cold front. Surface high will build in
behind the front Sun and Mon with flow out of the north through
the end of the period. Postfront Cold advection and pressure
gradient are of limited strength. Ahead of the cold front
southerly flow will be 15 to 20 kt but following the passage of
the front speeds will be be in the 10 to 15 kt range. Seas as high
as 5 ft will be possible Sat ahead of the front but development of
offshore flow combined with decreased wind speeds will drop seas
to 3 to 4 ft Sun and 2 to 4 ft Mon.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.

&&

$$

NEAR TERM...MJC
SHORT TERM...DCH
LONG TERM...III
AVIATION...SGL



  [top] Area Forecast Discussion National Weather Service Newport/Morehead City NC 837 PM EDT WED MAY 18 2016 .SYNOPSIS... Low pressure off the coast will continue to move northeast away from the area tonight. High pressure will extend into the area from the north Thursday and Friday. Low pressure will develop to the southwest late Friday night then lift northeast across the region Saturday. The low will lift northeast of the area Saturday night and Sunday pushing a cold front offshore. Low pressure will develop well offshore early next week as high pressure builds south of the region. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 730 PM Wednesday...Updated to indicate some clearing over northern sections this evening per latest obs/satellite trends. Still expect some lower cloudiness to develop...thus kept mostly cloudy/cloudy forecast for overnight. Minor adjustments for latest hourly temp/dew point trends. /Previous discussion/ As of 230 PM Wednesday...Rain has rapidly diminished across the region and will lower pops to slight chc thru early evening with patchy light rain or drizzle...mainly near coast. Any lingering precip should end by mid evening as drier mid level air spreads in. Low levels will remain nearly saturated and expect good deal of clouds to persist thru the night. Lows will be mainly in the mid to upper 50s...poss holding around 60 central/southern beaches. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... As of 230 PM Wednesday...High pressure will build N of the area with mainly dry weather expected. Bulk of models do show some increase in moisture and light qpf SW tier late ahead of weak short wave so added slight pop this area. Plenty of clouds will continue over the region and with NNE surface flow temps will remain cool with highs low/mid 70s with some 60s Outer Banks. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As of 3 pm Wednesday...A very active weather pattern with below normal temps through a portion of the period. Thursday Night through Friday Night: High pressure will migrate eastward through the Mid-Atlantic states during the period, eventually moving offshore by early Saturday. North flow will start to veer easterly Friday as the surface high shifts offshore. Southeast flow increases Friday night as the next storm system approaches from the southwest. Introduced slight chance pops Thursday night into Friday for the southerly third of the CWA as a weak boundary remains south of the area with moisture lingering. PWATS increase rapidly Friday afternoon/evening as southwesterly flow in the mid levels brings in greater moisture across the area. Precip chances increase from slight chance late Friday to likelies late Friday night, partly due to a warm front lifting north through the region. Temps Friday will range low/mid 70s due to precip/clouds. Thursday night lows will range in the mid 50s to near 60 along the OBX, and mid/upper 60s areawide on Friday night. Saturday through Monday: A developing surface low will shift northeast through Eastern NC on Saturday as an upper trough digs southeast from the Great Lakes into the Mid-Atlantic region. This will result in a surface low developing/moving north of the area Saturday with a cold front crossing Saturday afternoon/evening. Given we will be under the warm sector ahead of the front with ample lift, moisture and sufficient instability/shear, the convective potential looks probable, especially in the afternoon. The timing of this front and the subsequent cloud cover will be a big factor in the severity/coverage of any storms that develop. It is a bit far out to iron out details at this point, but looks like the front crossing around late afternoon will limit convection in the evening. The surface low will move off the Mid- Atlantic coast Sunday with the closed upper low becoming anchored across the Eastern CONUS through midweek. This will then provide continued cloud cover and slight chance showers through the remainder of the period. Temps will remain in the low/mid 70s during this period, with the cooler day being Sunday after the front crosses and a surge of cooler air moves into the region. Tuesday through Wednesday: The closed upper low will finally lift northeast into New England with zonal flow developing by Wednesday. Meanwhile, high pressure quickly builds in, shifting offshore by Wednesday ushering in warm return flow and more seasonable temperatures. High temps Tuesday will be in the upper 70s and rebound into the low/mid 80s by Wednesday. Given moisture return and modest instability, introduced slight chance showers and thunderstorms for Wednesday afternoon for inland sections. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... Short Term /Through 00Z Friday/... As of 730 PM Wednesday...Problematic forecast for this evening as guidance is not in good agreement with latest obs trends. Most of guidance indicatest current mainly MVFR cigs lowering to IFR by late evening with IFR/LIFR then persisting into Thursday morning. However obs and satellite indicate clearing moving into NW sections as slightly drier air mass is advecting in as low pressure moves offshore. Have gone with obs trend next few hours...but with diminishing winds and moist low levels...still expect some IFR stratus to develop 03Z-06z and persist into morning. Cigs will improve to VFR by 15Z...but some increased lift may result in MVFR cigs again after 21Z. Forecast confidence moderate at best. Long Term /Thursday Night through Monday/... As of 310 pm Wednesday...High pressure to the north will persist through Friday, then eventually shifts offshore Friday Night. Expect VFR conditions through Friday, with some mid level clouds returning Thursday night through Friday especially for OAJ/EWN. With return flow quickly developing Friday afternoon and the increase in precipitation, expect lowering ceilings with sub-VFR conditions likely. Ample moisture will be present Friday night through much of Saturday ahead of a front that is progged to cross later Saturday. Lingering sub-VFR conditions can be expected early Sunday. Drier air will work its way into the region through the remainder of Sunday and into Monday. However, do expect lingering mid/upper level clouds Sunday under north flow. Predominant VFR expected Monday. && .MARINE... Short Term /Tonight and Thursday/... As of 730 PM Wednesday...No changes with update. /Previous discussion/ As of 230 PM Wednesday...NNE winds remain quite gusty along the coast to N and W of low pressure located SE of Cape Lookout. Winds should remain up along the coast into the evening before diminishing overnight as low departs. Seas of 5 to 8 feet will continue over the coastal waters into this evening. Later tonight as the low moves further offshore winds will gradually diminish and seas are expected to subside below 6 feet by early Thursday morning. NNE winds will cont at 10 to 15 knots Thu with some gusts to around 20 knots northern and central waters as high pressure builds north of the area. Seas will be mainly 3 to 5 feet Thursday...quite a bit lower over waters near the coast south of Cape Lookout. Long Term /Thursday Night through Monday/... As of 320 pm Wednesday...High pressure will build across the waters from the north Thursday night into Friday, moving offshore late Friday ahead of the next storm system. Southeast winds will quickly increase Saturday ahead of a cold front set to cross the waters Saturday Night/early Sunday. Winds expected to be around 15-25kts with higher gusts. Seas will build by Saturday afternoon, to around 6 to 8 feet across the central waters. Behind the front, winds shift northwesterly Saturday night into early Sunday with wind speeds 10-20 kts, helping to maintain seas 4 to 6 feet across the northern waters through late Saturday night. Winds shift northerly Monday but continue mostly 5-15 kt, yielding seas 3-5 ft north to 2-4 ft south. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 2 AM EDT Thursday for AMZ135-150- 156-158. Small Craft Advisory until 6 AM EDT Thursday for AMZ152-154. && $$ SYNOPSIS...RF NEAR TERM...RF/JBM SHORT TERM...RF LONG TERM...DAG/LEP AVIATION...JBM/DAG/SGK MARINE...RF/JBM/DAG
  [top] Area Forecast Discussion National Weather Service Raleigh NC 750 PM EDT Wed May 18 2016 .SYNOPSIS...In the wake of a departing low pressure system...a cool surface high pressure system will build over the area tonight through Thursday. A low pressure system tracking east across the Southern states will bring wet unsettled conditions to the Carolinas late Friday through early Saturday. && .NEAR TERM /through tonight/... As of 330 PM Wednesday... A sfc wave continues to linger off the SE coast of NC this afternoon. This feature will drift farther offshore tonight...being pushed along by a s/w in the northern stream crossing southern new england. In its wake...a weak shear axis and attendant inverted sfc trough will drift east into western NC tonight/early Thu. This feature interacting with abundant low level moisture may trigger a few showers in the vicinity of the Yadkin River late this evening through the overnight. Widespread cloud cover will limit the normal nocturnal cooling. Min temps low-mid 50s north half with upper 50s south. && .SHORT TERM /Thursday and Thursday night/... As of 330 PM Wednesday... WRF models along with a few near term models have trended wetter than previous runs for Thursday...apparently keying on the weak shear axis and inverted sfc trough. The WRF models are likely overdone considering they are overplaying the rain showers this afternoon in vicinity of the higher terrain in western NC. While the GFS and ECMWF both depict the inverted sfc trough washing out...being replaced by a narrow ridge of high pressure...model guidance still depicting measurable rain over most of central NC on Thursday. Models may be keying on confluence along a west-to-east 850mb boundary in vicinity of highway 64. Cross sections, however, reveal that the lift, weak as it is, is confined to the lowest 8k ft or so of the atmosphere. Thus, having a tough time buying into the high end likely/low end categorical pops across the area for Thursday. Appears highest threat for measurable rain will be Thursday morning...and mainly confined to the far SW. After 16Z, rain chances should be no more than a chance and highest over the south. Extensive cloud cover and chances for precip will prevent temps from warming much above overnight low temps. High temps should vary from the low-mid 60s north to the lower 70s se. If rain is more extensive than forecast, high temp may end up being 3-5 degrees cooler. Weak isentropic upglide late Thursday night will yield spots of light rain...especially after 04Z and mainly over the sw third of the forecast area. Min temps generally in the mid-upper 50s. && .LONG TERM /Friday through Wednesday/... As of 230 PM Wednesday... Friday through Saturday: High pressure will be extending down the east coast to begin the long term period, with a cold air damming regime setting up over the region. At the same time, a short wave will be moving towards the area from the west and this will set the stage for a rather wet period. A couple of waves of low pressure are progged to track near/along the CAD boundary that will set up across the area. Precip chances will increase from west to east throughout the day on Friday, with the best time frame being Friday night/early Saturday morning. Given the high shear/low cape environment that is expected, the severe weather threat is expected to be rather low, especially given the poor diurnal timing. The bigger threat is going to be the heavy rain potential, where average rainfall amounts are expected to range from around an inch across the southeast to possibly around 2 inches or more across the Northwest Piedmont, which could cause some minor flooding in urban areas or poor drainage locations. The majority of the precip should shift off to the northeast throughout the afternoon on Saturday, although persistent cyclonic flow aloft will linger across the area and will result in mostly cloudy skies and possibly a lingering showers into Saturday night. Given the CAD regime, high temps should range from low/mid 70s across the southeast to the low/mid 60s across the northwest. Sunday through Wednesday: Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /00Z Thursday through Monday/... As of 750 PM Wednesday... Poor aviation conditions will continue overnight as low clouds persist in northeasterly flow. The areawide improvement to MVFR this afternoon should give way to at least IFR by 06z, with some lifr and rain/drizzle possible at KGSO and KINT by 12z. The light rain and drizzle is expected to shift east through the morning hours, though with some drier low-level air filtering in from the northeast, confidence in the coverage of precip is lower toward KRDU and KRWI. There should be some slow improvement of ceilings in the east by midday, to MVFR and possibly VFR at KFAY by Thursday evening. Abundant moisture will continue the threat of low ceilings through Friday night. A strong low pressure system and cold front will cross the region on Saturday, helping to scour low-level moisture and bring VFR conditions for Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...WSS LONG TERM...KRD AVIATION...22
Area Forecast Discussion National Weather Service Wilmington NC 756 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build from the north overnight into Thursday. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 704 PM Wednesday...No significant changes required with the early evening updates as mostly cloudy skies prevail with local temperatures overnight very close to climatology for this time of May. No drivers for significant PCPN tonight aside from MCV perturbation showers west of I-95 after 3 AM. Low level saturation late tonight may materialize a patch or 2 of drizzle, but for most locations, measurable rainfall is not likely. With low cloud ceilings and nearly saturated low level air, temperature drops will be slow to evolve, settling in the upper 50s to lower 60s daybreak Thursday. A pocket of mist or fog cannot be ruled out overnight as well given the very damp regime in place near the surface. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 00Z...MVFR with brief improvement to VFR possible this evening before widespread MVFR/IFR returns with areas of fog possible overnight. Improvement to VFR on Thursday is expected with increasing chances for showers throughout the day. Though latest radar imagery remains fairly quiet this evening, satellite imagery continues to show broken to overcast coverage of low clouds allowing for widespread MVFR to prevail at the terminals. Trends do indicate the potential for brief improvement to VFR over the next few hours, before cloud coverage increases again overnight. This along with developing areas of fog will create MVFR/IFR through the early morning hours. Light and variable winds are expected. After daybreak, expect conditions to improve to VFR with increasing chances for showers into the afternoon hours. Northeasterly winds around 5 kts in the morning will become east-northeasterly in the afternoon around around 10 kts. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 704 PM Wednesday...`Exercise Caution" headline is needed for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly mellower wind-speeds over the SC waters precludes this headline. Caution headline valid until midnight tonight as wind trends ease this evening, as a low offshore of Cape Lookout moves NE away from the coast...thus a very brief cautionary period. Virtually no wave energy with wave periods greater than 7 seconds exists right now and all energy is tied to nearby winds...thus slightly steep and bumpy this evening for only 3-5 ft seas. Dominant wave periods will hold between 6-7 seconds overnight with little or no shower activity. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MJC SHORT TERM...DCH LONG TERM...III AVIATION...SGL
Area Forecast Discussion National Weather Service Wilmington NC 704 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build from the north overnight into Thursday. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 704 PM Wednesday...No significant changes required with the early evening updates as mostly cloudy skies prevail with local temperatures overnight very close to climatology for this time of May. No drivers for significant PCPN tonight aside from MCV perturbation showers west of I-95 after 3 AM. Low level saturation late tonight may materialize a patch or 2 of drizzle, but for most locations, measurable rainfall is not likely. With low cloud ceilings and nearly saturated low level air, temperature drops will be slow to evolve, settling in the upper 50s to lower 60s daybreak Thursday. A pocket of mist or fog cannot be ruled out overnight as well given the very damp regime in place near the surface. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 18Z... Low clouds will be persistent through the period. However through the afternoon they may tend to occasionally break from IFR to MVFR. With the loss of daytime heating lower ceilings will become more favorable, though not all model guidance indicates such. Have opted to keep with the more pessimistic view which does in fact sock the area in with IFR overnight and show improvement to MVFR a few hours after daybreak Thursday. Any visibility restrictions will be minor, MVFR-ish. Little to no precipitation is expected. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 704 PM Wednesday...`Exercise Caution" headline is needed for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly mellower wind-speeds over the SC waters precludes this headline. Caution headline valid until midnight tonight as wind trends ease this evening, as a low offshore of Cape Lookout moves NE away from the coast...thus a very brief cautionary period. Virtually no wave energy with wave periods greater than 7 seconds exists right now and all energy is tied to nearby winds...thus slightly steep and bumpy this evening for only 3-5 ft seas. Dominant wave periods will hold between 6-7 seconds overnight with little or no shower activity. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MJC SHORT TERM...DCH LONG TERM...III AVIATION...SGL
Area Forecast Discussion National Weather Service Wilmington NC 337 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build in from the north overnight. A stalled front will move north across the area Friday as a warm front. A surface low will pass over or just west of the area late Friday night and drag a cold front across the area Saturday. Showers and thunderstorms are likely ahead of the front. Clouds and showers may linger on Sunday under low pressure aloft. The low will slowly move away from the area Monday through Wednesday with dry and seasonable conditions returning by the middle of next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 3 PM Wednesday...Models are in a decent consensus with sfc ridging from the north dominating thru early fri, with the highs center moving from the great lakes on Thu, to the NE States by early Fri. For Fri thru Fri night is when models detour from one another with respect to the eventual inland movement of the coastal front. Some mid and upper level drying early Thu will slowly moisten thruout the atm column by late Thu. Overrunning type pcpn will begin mid to late day Thu and persist thru Thu night into daytime Fri. some timing issues will exist afterwards from Fri aftn thru Fri night with regard to the coastal front lifting inland and eventually northward across the ilm cwa. Thu thru early Fri pcpn will be limited to mainly overrunning type pcpn with embedded heavier showers possible. Any thunder will remain south and east of the ILM CWA closer to where the frontal boundary lies and to where it bends inland over southern SC. For daytime Fri thru Fri night...the ILM CWA will be subject to heavier pcpn with overrunning light showers/rain dominating initially. As the coastal front pushes inland and at the same time lifting northward, the fa will find itself in the warm sector by daybreak sat. thus, convective type pcpn will eventually become the dominant type. this will also be reflected within the qpf fields. Stayed with a consensus of available model mos guidance thru daytime Fri...which basically keeps mid to upper 70s for highs, and upper 50s inland to low 60s at the coast for lows. For Fri night, the fa will see widespread 60s to near 70 at the coast for Sat lows. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... As of 18Z... Low clouds will be persistent through the period. However through the afternoon they may tend to occasionally break from IFR to MVFR. With the loss of daytime heating lower ceilings will become more favorable, though not all model guidance indicates such. Have opted to keep with the more pessimistic view which does in fact sock the area in with IFR overnight and show improvement to MVFR a few hours after daybreak Thursday. Any visibility restrictions will be minor, MVFR-ish. Little to no precipitation is expected. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes Thursday morning will push east to the NE States by Fri, and off the NE States Coast Fri night. Sfc ridging from the highs center will extend south/down the east coast. at the same time, a stalled frontal boundary or coastal front will lie just offshore and parallel to the ILM CWA coastline, before bending back westward and inland in the vicinity of the SC and GA Border. As a result, the local waters will be subject to a ne-ene wind direction thru early Fri. A somewhat tightened sfc pg will exist thruout the period, with wind speeds generally in the 10 to 20 kt range. From midday Fri thru Fri night...the frontal boundary offshore and south of the area waters...will push inland and lift northward at the same time. This boundary is expected to push inland during Fri night with winds veering from the e to se Fri Evening...and further veering to the South by daybreak Sat. Wind speeds will remain 10 to 20 kt especially after the front pushes onshore. Significant seas will mainly be a function of wind driven waves, with dominating periods increasing from 4 to 5 seconds early Thu to 6 to 7 seconds on Fri. Sea Heights will likely reach SCEC Thresholds Thu Night, and possibly SCA Thresholds during Fri. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...DCH SHORT TERM...DCH LONG TERM...III AVIATION...MBB
Area Forecast Discussion National Weather Service Newport/Morehead City NC 324 PM EDT WED MAY 18 2016 .SYNOPSIS... Low pressure off the coast will continue to move northeast away from the area tonight. High pressure will extend into the area from the north Thursday and Friday. Low pressure will develop to the southwest late Friday night then lift northeast across the region Saturday. The low will lift northeast of the area Saturday night and Sunday pushing a cold front offshore. Low pressure will develop well offshore early next week as high pressure builds south of the region. && .NEAR TERM /THROUGH TONIGHT/... As of 230 PM Wednesday...Rain has rapidly diminished across the region and will lower pops to slight chc thru early evening with patchy light rain or drizzle...mainly near coast. Any lingering precip should end by mid evening as drier mid level air spreads in. Low levels will remain nearly saturated and expect good deal of clouds to persist thru the night. Lows will be mainly in the mid to upper 50s...poss holding around 60 central/southern beaches. && .SHORT TERM /THURSDAY/... As of 230 PM Wednesday...High pressure will build N of the area with mainly dry weather expected. Bulk of models do show some increase in moisture and light qpf SW tier late ahead of weak short wave so added slight pop this area. Plenty of clouds will continue over the region and with NNE surface flow temps will remain cool with highs low/mid 70s with some 60s Outer Banks. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As of 3 pm Wednesday...A very active weather pattern with below normal temps through a portion of the period. Thursday Night through Friday Night: High pressure will migrate eastward through the Mid-Atlantic states during the period, eventually moving offshore by early Saturday. North flow will start to veer easterly Friday as the surface high shifts offshore. Southeast flow increases Friday night as the next storm system approaches from the southwest. Introduced slight chance pops Thursday night into Friday for the southerly third of the CWA as a weak boundary remains south of the area with moisture lingering. PWATS increase rapidly Friday afternoon/evening as southwesterly flow in the mid levels brings in greater moisture across the area. Precip chances increase from slight chance late Friday to likelies late Friday night, partly due to a warm front lifting north through the region. Temps Friday will range low/mid 70s due to precip/clouds. Thursday night lows will range in the mid 50s to near 60 along the OBX, and mid/upper 60s areawide on Friday night. Saturday through Monday: A developing surface low will shift northeast through Eastern NC on Saturday as an upper trough digs southeast from the Great Lakes into the Mid-Atlantic region. This will result in a surface low developing/moving north of the area Saturday with a cold front crossing Saturday afternoon/evening. Given we will be under the warm sector ahead of the front with ample lift, moisture and sufficient instability/shear, the convective potential looks probable, especially in the afternoon. The timing of this front and the subsequent cloud cover will be a big factor in the severity/coverage of any storms that develop. It is a bit far out to iron out details at this point, but looks like the front crossing around late afternoon will limit convection in the evening. The surface low will move off the Mid- Atlantic coast Sunday with the closed upper low becoming anchored across the Eastern CONUS through midweek. This will then provide continued cloud cover and slight chance showers through the remainder of the period. Temps will remain in the low/mid 70s during this period, with the cooler day being Sunday after the front crosses and a surge of cooler air moves into the region. Tuesday through Wednesday: The closed upper low will finally lift northeast into New England with zonal flow developing by Wednesday. Meanwhile, high pressure quickly builds in, shifting offshore by Wednesday ushering in warm return flow and more seasonable temperatures. High temps Tuesday will be in the upper 70s and rebound into the low/mid 80s by Wednesday. Given moisture return and modest instability, introduced slight chance showers and thunderstorms for Wednesday afternoon for inland sections. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... Short Term /Through Thursday Afternoon/... As of 145 pm Wed...IFR conditions are present across the region due to ceilings just under 1000 feet. Expecting ceilings to rise another couple hundred feet this afternoon...which will raise conditions to MVFR. However IFR ceilings will return after or near midnight with continued northeast flow and trapped low level moisture. LIFR conditions could be met early Thursday morning but will hold off on mentioning them in the TAF for this issuance. Fog looks unlikely due to a lingering light breeze overnight but patchy fog cannot be ruled out. VFR conditions should return after 8 or 9 am Thursday under continued cloudy skies. Long Term /Thursday Night through Monday/... As of 310 pm Wednesday...High pressure to the north will persist through Friday, then eventually shifts offshore Friday Night. Expect VFR conditions through Friday, with some mid level clouds returning Thursday night through Friday especially for OAJ/EWN. With return flow quickly developing Friday afternoon and the increase in precipitation, expect lowering ceilings with sub-VFR conditions likely. Ample moisture will be present Friday night through much of Saturday ahead of a front that is progged to cross later Saturday. Lingering sub-VFR conditions can be expected early Sunday. Drier air will work its way into the region through the remainder of Sunday and into Monday. However, do expect lingering mid/upper level clouds Sunday under north flow. Predominant VFR expected Monday. && .MARINE... Short Term /Tonight and Thursday/... As of 230 PM Wednesday...NNE winds remain quite gusty along the coast to N and W of low pressure located SE of Cape Lookout. Winds should remain up along the coast into the evening before diminishing overnight as low departs. Seas of 5 to 8 feet will continue over the coastal waters into this evening. Later tonight as the low moves further offshore winds will gradually diminish and seas are expected to subside below 6 feet by early Thursday morning. NNE winds will cont at 10 to 15 knots Thu with some gusts to around 20 knots northern and central waters as high pressure builds north of the area. Seas will be mainly 3 to 5 feet Thursday...quite a bit lower over waters near the coast south of Cape Lookout. Long Term /Thursday Night through Monday/... As of 320 pm Wednesday...High pressure will build across the waters from the north Thursday night into Friday, moving offshore late Friday ahead of the next storm system. Southeast winds will quickly increase Saturday ahead of a cold front set to cross the waters Saturday Night/early Sunday. Winds expected to be around 15-25kts with higher gusts. Seas will build by Saturday afternoon, to around 6 to 8 feet across the central waters. Behind the front, winds shift northwesterly Saturday night into early Sunday with wind speeds 10-20 kts, helping to maintain seas 4 to 6 feet across the northern waters through late Saturday night. Winds shift northerly Monday but continue mostly 5-15 kt, yielding seas 3-5 ft north to 2-4 ft south. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 2 AM EDT Thursday for AMZ135-150- 156-158. Small Craft Advisory until 6 AM EDT Thursday for AMZ152-154. && $$ SYNOPSIS...RF NEAR TERM...RF SHORT TERM...RF LONG TERM...DAG/LEP AVIATION...DAG/SGK MARINE...RF/DAG
Area Forecast Discussion National Weather Service Raleigh NC 237 PM EDT Wed May 18 2016 .SYNOPSIS...In the wake of a departing low pressure system...a cool surface high pressure system will build over the area tonight through Thursday. A low pressure system tracking east across the Southern states will bring wet unsettled conditions to the Carolinas late Friday through early Saturday. && .NEAR TERM /through tonight/... As of 1030 AM Wednesday... Upper air analysis depict a weak low level trough over the ne sector of central NC. Weak confluence along this boundary in conjunction with modest lift aloft associated with divergence in the right entrance region of a 110+ kt jet exiting the northern Mid-Atlantic was causing spots of light rain/drizzle across sections of central NC this morning. The patches of light rain/drizzle will diminish with time and lift becomes weaker. Abundant low level moisture will be tough to scour out due to lack of sufficient mixing of drier air...thus a blanket of low stratus will persist into the afternoon hours. Area MDCRS aircraft soundings suggest the cloud thickness about a 1000ft or a little less. This suggest that some breaks may occur late in the day...though likely too late to add in temp recovery. Low overcast skies and a steady near sfc ne wind will hold temps well below normal for mid-May. Afternoon temps will top out in the mid-upper 60s north to near 70-lower 70s south. -WSS Ceilings are expected to quickly fall/lower after sunset with IFR to LIFR conditions expected everywhere overnight. Continued weak upglide along the eastern slopes of the mtns will continue to support a slight to small chance of rain, mainly across the western Piedmont. Lows tonight in the lower 50s north to upper 50s south. -CBL && .SHORT TERM /Thursday and Thursday night/... As of 345 AM Wednesday... Parent high center will build over the Mid-Atlantic Seaboard on Thursday with low-level wedge of cooler and drier air ridging south into the area underneath continued WSW flow aloft, within the right entrance region of a ~90kt upper jet streak in place over the Mid- Atlantic region. Low clouds/moisture will persist but sufficient forcing is absent over the area during the day on Thursday. So expect a gray gloomy day across the area with continued below normal temperatures in the mid/upper 60s north to lower 70s south. Weak upglide begins to strengthen Thursday night, in response to mid- level shortwave trough and sfc cyclogenesis over the lower MS/TN Valleys. Better rain chances will remain to our west but will continue to indicate isolated/slight chance pops across the far southern/southwestern zones with onset of In-situ Damming expected. Lows again in the lower 50s to upper 50s, coolest ne. && .LONG TERM /Friday through Wednesday/... As of 230 PM Wednesday... Friday through Saturday: High pressure will be extending down the east coast to begin the long term period, with a cold air damming regime setting up over the region. At the same time, a short wave will be moving towards the area from the west and this will set the stage for a rather wet period. A couple of waves of low pressure are progged to track near/along the CAD boundary that will set up across the area. Precip chances will increase from west to east throughout the day on Friday, with the best time frame being Friday night/early Saturday morning. Given the high shear/low cape environment that is expected, the severe weather threat is expected to be rather low, especially given the poor diurnal timing. The bigger threat is going to be the heavy rain potential, where average rainfall amounts are expected to range from around an inch across the southeast to possibly around 2 inches or more across the Northwest Piedmont, which could cause some minor flooding in urban areas or poor drainage locations. The majority of the precip should shift off to the northeast throughout the afternoon on Saturday, although persistent cyclonic flow aloft will linger across the area and will result in mostly cloudy skies and possibly a lingering showers into Saturday night. Given the CAD regime, high temps should range from low/mid 70s across the southeast to the low/mid 60s across the northwest. Sunday through Wednesday: Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /18Z Wednesday through Monday/... As of 120 pm Wednesday... There is a high likelihood that mvfr/ifr ceilings will persist across central NC through tonight. In addition, there will be pockets of mvfr/ifr fog developing after 05Z. Spots of light rain will be possible in vicinity of the Triad terminals toward daybreak...possibly heading into the KRDU vicinity by mid morning. Abundant low level moisture will maintain a deck of low clouds across central NC through early friday...and possibly through Saturday morning. A pair of weak low pressure systems will increase the threat for rain showers across central NC. The initial wave will bring an enhanced threat for showers late Thursday night to the southern counties including the KFAY vicinity. The later wave...forecast to be stronger...will increase the threat for showers across most of central NC Friday night into Saturday morning. Improving aviation conditions are expected by late Saturday...with a good probability of vfr conditions Sunday and Monday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...wss NEAR TERM...WSS/CBL SHORT TERM...CBL LONG TERM...KRD AVIATION...wss Area Forecast Discussion National Weather Service Raleigh NC 305 AM EDT Thu May 19 2016 .SYNOPSIS...An upper level disturbance will push across the region today. A weak and cool surface high pressure will continue to extend into central North Carolina through Friday. A much stronger storm system is expected to move into the region late Friday into early Saturday. && .NEAR TERM /through tonight/... As of 122 AM Thursday... The main issues to deal with today will be the rain chances associated with the upper disturbance, and the expected persistent chilly NE low level supply of cool stable air and overcast associated with the hybrid CAD, resulting in temperatures again 20- 25 degrees below normal for highs. The predominate NE flow continued along the Appalachians and east coast states this morning, courtesy of the low pressure exiting into the western Atlantic and the surface high pressure located over the lower Great Lakes states. This flow is one that continues to advect cool and some marginally drier air into the state from central VA. The NE-E flow extended all the way into central SC and northeast GA where a weak low pressure was noted. Some drier air was trying to work down the coast from the north with some partial clearing of the low clouds noted east of I-95. There was a weakness in the pressure pattern noted over the Appalachians associated with the current weak hybrid CAD high pressure over NC/VA and the stronger high located over the lower Great Lakes states. Radar indicated scattered showers and thunderstorms developing over upstate SC spreading NE into western NC to near Hickory and Statesville. This is area was associated with the approaching upper level disturbance and the mass convergence near the surface wave and front stalled over upstate SC. For the chances of rain today, the latest Hi-Res convection allowing models support the current radar trends in bringing an area of showers and general rain (north in the cool stable air) across the Piedmont this morning. This occurs as the low level flow remains NE bringing a continuous supply of cool stable air into the Piedmont Damming region. This scenario above is favored by the conventional GFS/NAM as well. MOS guidance finally caught up with the much cooler stable temperatures yesterday associated with the NE flow and damming; therefore, we will not have to adjust guidance down as much today as we did yesterday. Bottom line today, expect a good chance of showers in the SE Coastal Plain with occasional rain over the Piedmont. Most of the rain should be light with QPF of around 0.25 expected in the Piedmont, lesser amounts over the Coastal Plain. Temperatures should only go up 3-5 degrees or so as the low overcast develops/persists through the day. Highs only in the 50s NW and N Piedmont ranging into the upper 60s SE. Significant rain chances lower tonight in the rear of the upper disturbance departing to the NE. However, the low overcast conditions should continue tonight enhanced by the low level NNE flow. In fact, the main chilly surface high pressure is forecast to move east to PA later tonight. The high is of sufficient strength and in a proper position to deliver additional cool stable air into the region to allow for the persistence of the CAD, then enhancement of the CAD Friday into Friday night as the next storm approaches from the SW (see discussion below). Lows tonight 50s except lower 60s SE. && .SHORT TERM /Friday through Saturday/... As of 258 aM Thursday... ...Hybrid CAD and Miller B storm system to affect the region into early Saturday... Issues ahead for Friday through Saturday will be mainly with the rainfall forecasts and the continued very cool temperatures for daily highs through at least Saturday. Any severe threat associated with the approaching storm system late Friday and Friday night have essentially been erased by the agreement of the models with hybrid CAD over our region and by the forecast of the storm track to be up along or east of I-95 late Friday night and early Saturday. This storm track is more of a Miller B with one low lifting NE through the TN and OH valley as another develops along the SC/NC coastal area late Friday night, then tracks up the coast Saturday. This pattern has a cool stable and almost "wintry" look to it. To begin Friday, a very cool surface high pressure is forecast to be centered over PA. The strength is expected to be around 1025 MB. The location and strength are both sufficient to deliver additional cool stable air into central NC from the north Friday. This occurs as the initial low pressure is forecast to track NE into the TN valley region by late Friday. All of our region is expected to be dominated by the cool stable low level high to the north. As such, temperatures Friday will be hard pressed to get out of the 60s anywhere in the region. Some upper 50s may again linger around the Triad to Roxboro in the continued hybrid CAD resume. The CAD will be strengthen as the day goes on as a cool stable NE flow pumps into the damming region of the Piedmont. Models suggest that some areas of light rain may develop/overspread portions of the Piedmont during the afternoon before widespread rain arrives Friday night. Even though the parent surface high will move offshore of New England Friday, the cool stable dome will have already been enhanced and firmly established. The coastal front is forecast to be pinned at the immediate coast. As one storm lifts NE toward the central Appalachians, another one will develop and take over near the boundary along the SC coast Friday night. This low will then lift NE along the coast early Saturday. There will be very little chance in this scenario of the coastal front being pulled inland, thus eliminating the severe risk over our region. However, a few elevated thunderstorms are expected to be embedded in the large rain area that overspreads the region Friday night, then ends from the southwest Saturday morning. The storm will then lift away from the region Saturday afternoon with dramatically lowering POP. However... the northerly flow behind the system along with lingering moisture in the low levels should keep any partial clearing confined to the SW Piedmont Saturday afternoon. Highs will be held down again by the residual CAD and then the persistent northerly flow as the storm pulls away. Expect readings to be warmest where any breaks occur in the SW Piedmont (possibly near 70). Most areas will stay in the lower to mid 60s (which is a good 20 degrees below normal). QPF will continue to be a tough call given the complexity of the evolving storm and the hybrid CAD over inland areas. Not to mention the deep south/Gulf coast convection potential. Even though models continue to be generous with 1 to locally 1.5 inches, this may be overdone in some areas. Flash flooding is not anticipated with the lack of strong convection and with the FFG values running rather high in the 3+ inch range in 6 hours. This is not expected to be threatened. But 1 to 1.5 inches in 6 hours may result in some minor flooding in urban and flood prone areas. && .LONG TERM /Saturday night through Wednesday/... As of 3 AM Thursday... Additional energy is expected to dive southward out of Canada helping to close off into a mid/upper level low along the mid atlantic coast late weekend into early next week, which will result in continue chances for showers and possibly some storms depending on the placement of the mid/upper low for Sunday and Monday (chance of convection everywhere for Sunday and limited to just eastern portions of the area my Monday). However, the best chance for precip will be during the afternoon into the evening/more diurnally driven convection. Highs Sunday and Monday are expected to remaining below normal in the 70s. Highs Tuesday and Wednesday will return to more seasonable values as the mid/upper low is expected to lift off to the northeast and surface high pressure is expected to shift offshore finally. Lows temps are expected to be near to slightly below normal for the medium range. && .AVIATION /06Z Thursday through Monday/... As of 125 AM Thursday... Low ceilings and occasionally low visibilities as well will persist today and tonight. Occasional rain and drizzle can be expected in the region along with persistent MVFR becoming IFR CIGS at or below 1K feet today. Abundant moisture will continue the low ceilings through tonight and into Friday. However, surface visibilities should improve somewhat Friday before falling again to IFR with rain and fog late Friday into Saturday morning. This occurs as a low level NE flow strengthens out ahead of an approaching storm system from the SW Friday night. This storm is expected to lift N of the region Saturday afternoon. The outlook for Saturday late through Sunday is for improving aviation conditions as the widespread rain/fog move north of the region between 12z-18z Saturday. VFR conditions are expected Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...Badgett/BSD LONG TERM...BSD AVIATION...Badgett
Area Forecast Discussion National Weather Service Raleigh NC 258 AM EDT Thu May 19 2016 .SYNOPSIS...An upper level disturbance will push across the region today. A weak and cool surface high pressure will continue to extend into central North Carolina through Friday. A much stronger storm system is expected to move into the region late Friday into early Saturday. && .NEAR TERM /through tonight/... As of 122 AM Thursday... The main issues to deal with today will be the rain chances associated with the upper disturbance, and the expected persistent chilly NE low level supply of cool stable air and overcast associated with the hybrid CAD, resulting in temperatures again 20- 25 degrees below normal for highs. The predominate NE flow continued along the Appalachians and east coast states this morning, courtesy of the low pressure exiting into the western Atlantic and the surface high pressure located over the lower Great Lakes states. This flow is one that continues to advect cool and some marginally drier air into the state from central VA. The NE-E flow extended all the way into central SC and northeast GA where a weak low pressure was noted. Some drier air was trying to work down the coast from the north with some partial clearing of the low clouds noted east of I-95. There was a weakness in the pressure pattern noted over the Appalachians associated with the current weak hybrid CAD high pressure over NC/VA and the stronger high located over the lower Great Lakes states. Radar indicated scattered showers and thunderstorms developing over upstate SC spreading NE into western NC to near Hickory and Statesville. This is area was associated with the approaching upper level disturbance and the mass convergence near the surface wave and front stalled over upstate SC. For the chances of rain today, the latest Hi-Res convection allowing models support the current radar trends in bringing an area of showers and general rain (north in the cool stable air) across the Piedmont this morning. This occurs as the low level flow remains NE bringing a continuous supply of cool stable air into the Piedmont Damming region. This scenario above is favored by the conventional GFS/NAM as well. MOS guidance finally caught up with the much cooler stable temperatures yesterday associated with the NE flow and damming; therefore, we will not have to adjust guidance down as much today as we did yesterday. Bottom line today, expect a good chance of showers in the SE Coastal Plain with occasional rain over the Piedmont. Most of the rain should be light with QPF of around 0.25 expected in the Piedmont, lesser amounts over the Coastal Plain. Temperatures should only go up 3-5 degrees or so as the low overcast develops/persists through the day. Highs only in the 50s NW and N Piedmont ranging into the upper 60s SE. Significant rain chances lower tonight in the rear of the upper disturbance departing to the NE. However, the low overcast conditions should continue tonight enhanced by the low level NNE flow. In fact, the main chilly surface high pressure is forecast to move east to PA later tonight. The high is of sufficient strength and in a proper position to deliver additional cool stable air into the region to allow for the persistence of the CAD, then enhancement of the CAD Friday into Friday night as the next storm approaches from the SW (see discussion below). Lows tonight 50s except lower 60s SE. && .SHORT TERM /Friday through Saturday/... As of 258 aM Thursday... ...Hybrid CAD and Miller B storm system to affect the region into early Saturday... Issues ahead for Friday through Saturday will be mainly with the rainfall forecasts and the continued very cool temperatures for daily highs through at least Saturday. Any severe threat associated with the approaching storm system late Friday and Friday night have essentially been erased by the agreement of the models with hybrid CAD over our region and by the forecast of the storm track to be up along or east of I-95 late Friday night and early Saturday. This storm track is more of a Miller B with one low lifting NE through the TN and OH valley as another develops along the SC/NC coastal area late Friday night, then tracks up the coast Saturday. This pattern has a cool stable and almost "wintry" look to it. To begin Friday, a very cool surface high pressure is forecast to be centered over PA. The strength is expected to be around 1025 MB. The location and strength are both sufficient to deliver additional cool stable air into central NC from the north Friday. This occurs as the initial low pressure is forecast to track NE into the TN valley region by late Friday. All of our region is expected to be dominated by the cool stable low level high to the north. As such, temperatures Friday will be hard pressed to get out of the 60s anywhere in the region. Some upper 50s may again linger around the Triad to Roxboro in the continued hybrid CAD resume. The CAD will be strengthen as the day goes on as a cool stable NE flow pumps into the damming region of the Piedmont. Models suggest that some areas of light rain may develop/overspread portions of the Piedmont during the afternoon before widespread rain arrives Friday night. Even though the parent surface high will move offshore of New England Friday, the cool stable dome will have already been enhanced and firmly established. The coastal front is forecast to be pinned at the immediate coast. As one storm lifts NE toward the central Appalachians, another one will develop and take over near the boundary along the SC coast Friday night. This low will then lift NE along the coast early Saturday. There will be very little chance in this scenario of the coastal front being pulled inland, thus eliminating the severe risk over our region. However, a few elevated thunderstorms are expected to be embedded in the large rain area that overspreads the region Friday night, then ends from the southwest Saturday morning. The storm will then lift away from the region Saturday afternoon with dramatically lowering POP. However... the northerly flow behind the system along with lingering moisture in the low levels should keep any partial clearing confined to the SW Piedmont Saturday afternoon. Highs will be held down again by the residual CAD and then the persistent northerly flow as the storm pulls away. Expect readings to be warmest where any breaks occur in the SW Piedmont (possibly near 70). Most areas will stay in the lower to mid 60s (which is a good 20 degrees below normal). QPF will continue to be a tough call given the complexity of the evolving storm and the hybrid CAD over inland areas. Not to mention the deep south/Gulf coast convection potential. Even though models continue to be generous with 1 to locally 1.5 inches, this may be overdone in some areas. Flash flooding is not anticipated with the lack of strong convection and with the FFG values running rather high in the 3+ inch range in 6 hours. This is not expected to be threatened. But 1 to 1.5 inches in 6 hours may result in some minor flooding in urban and flood prone areas. && .LONG TERM /Saturday night through Wednesday/... As of 230 PM Wednesday... Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /06Z Thursday through Monday/... As of 125 AM Thursday... Low ceilings and occasionally low visibilities as well will persist today and tonight. Occasional rain and drizzle can be expected in the region along with persistent MVFR becoming IFR CIGS at or below 1K feet today. Abundant moisture will continue the low ceilings through tonight and into Friday. However, surface visibilities should improve somewhat Friday before falling again to IFR with rain and fog late Friday into Saturday morning. This occurs as a low level NE flow strengthens out ahead of an approaching storm system from the SW Friday night. This storm is expected to lift N of the region Saturday afternoon. The outlook for Saturday late through Sunday is for improving aviation conditions as the widespread rain/fog move north of the region between 12z-18z Saturday. VFR conditions are expected Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...Badgett/BSD LONG TERM...KRD AVIATION...Badgett
Area Forecast Discussion National Weather Service Raleigh NC 122 AM EDT Thu May 19 2016 .SYNOPSIS...An upper level disturbance will push across the region today. A weak and cool surface high pressure will continue to extend into central North Carolina through Friday. A much stronger storm system is expected to move into the region late Friday into early Saturday. && .NEAR TERM /through tonight/... As of 122 AM Thursday... The main issues to deal with today will be the rain chances associated with the upper disturbance, and the expected persistent chilly NE low level supply of cool stable air and overcast associated with the hybrid CAD, resulting in temperatures again 20- 25 degrees below normal for highs. The predominate NE flow continued along the Appalachians and east coast states this morning, courtesy of the low pressure exiting into the western Atlantic and the surface high pressure located over the lower Great Lakes states. This flow is one that continues to advect cool and some marginally drier air into the state from central VA. The NE-E flow extended all the way into central SC and northeast GA where a weak low pressure was noted. Some drier air was trying to work down the coast from the north with some partial clearing of the low clouds noted east of I-95. There was a weakness in the pressure pattern noted over the Appalachians associated with the current weak hybrid CAD high pressure over NC/VA and the stronger high located over the lower Great Lakes states. Radar indicated scattered showers and thunderstorms developing over upstate SC spreading NE into western NC to near Hickory and Statesville. This is area was associated with the approaching upper level disturbance and the mass convergence near the surface wave and front stalled over upstate SC. For the chances of rain today, the latest Hi-Res convection allowing models support the current radar trends in bringing an area of showers and general rain (north in the cool stable air) across the Piedmont this morning. This occurs as the low level flow remains NE bringing a continuous supply of cool stable air into the Piedmont Damming region. This scenario above is favored by the conventional GFS/NAM as well. MOS guidance finally caught up with the much cooler stable temperatures yesterday associated with the NE flow and damming; therefore, we will not have to adjust guidance down as much today as we did yesterday. Bottom line today, expect a good chance of showers in the SE Coastal Plain with occasional rain over the Piedmont. Most of the rain should be light with QPF of around 0.25 expected in the Piedmont, lesser amounts over the Coastal Plain. Temperatures should only go up 3-5 degrees or so as the low overcast develops/persists through the day. Highs only in the 50s NW and N Piedmont ranging into the upper 60s SE. Significant rain chances lower tonight in the rear of the upper disturbance departing to the NE. However, the low overcast conditions should continue tonight enhanced by the low level NNE flow. In fact, the main chilly surface high pressure is forecast to move east to PA later tonight. The high is of sufficient strength and in a proper position to deliver additional cool stable air into the region to allow for the persistence of the CAD, then enhancement of the CAD Friday into Friday night as the next storm approaches from the SW (see discussion below). Lows tonight 50s except lower 60s SE. && .SHORT TERM /Thursday and Thursday night/... As of 330 PM Wednesday... WRF models along with a few near term models have trended wetter than previous runs for Thursday...apparently keying on the weak shear axis and inverted sfc trough. The WRF models are likely overdone considering they are overplaying the rain showers this afternoon in vicinity of the higher terrain in western NC. While the GFS and ECMWF both depict the inverted sfc trough washing out...being replaced by a narrow ridge of high pressure...model guidance still depicting measurable rain over most of central NC on Thursday. Models may be keying on confluence along a west-to-east 850mb boundary in vicinity of highway 64. Cross sections, however, reveal that the lift, weak as it is, is confined to the lowest 8k ft or so of the atmosphere. Thus, having a tough time buying into the high end likely/low end categorical pops across the area for Thursday. Appears highest threat for measurable rain will be Thursday morning...and mainly confined to the far SW. After 16Z, rain chances should be no more than a chance and highest over the south. Extensive cloud cover and chances for precip will prevent temps from warming much above overnight low temps. High temps should vary from the low-mid 60s north to the lower 70s se. If rain is more extensive than forecast, high temp may end up being 3-5 degrees cooler. Weak isentropic upglide late Thursday night will yield spots of light rain...especially after 04Z and mainly over the sw third of the forecast area. Min temps generally in the mid-upper 50s. && .LONG TERM /Friday through Wednesday/... As of 230 PM Wednesday... Friday through Saturday: High pressure will be extending down the east coast to begin the long term period, with a cold air damming regime setting up over the region. At the same time, a short wave will be moving towards the area from the west and this will set the stage for a rather wet period. A couple of waves of low pressure are progged to track near/along the CAD boundary that will set up across the area. Precip chances will increase from west to east throughout the day on Friday, with the best time frame being Friday night/early Saturday morning. Given the high shear/low cape environment that is expected, the severe weather threat is expected to be rather low, especially given the poor diurnal timing. The bigger threat is going to be the heavy rain potential, where average rainfall amounts are expected to range from around an inch across the southeast to possibly around 2 inches or more across the Northwest Piedmont, which could cause some minor flooding in urban areas or poor drainage locations. The majority of the precip should shift off to the northeast throughout the afternoon on Saturday, although persistent cyclonic flow aloft will linger across the area and will result in mostly cloudy skies and possibly a lingering showers into Saturday night. Given the CAD regime, high temps should range from low/mid 70s across the southeast to the low/mid 60s across the northwest. Sunday through Wednesday: Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /06Z Thursday through Monday/... As of 125 AM Thursday... Low ceilings and occasionally low visibilities as well will persist today and tonight. Occasional rain and drizzle can be expected in the region along with persistent MVFR becoming IFR CIGS at or below 1K feet today. Abundant moisture will continue the low ceilings through tonight and into Friday. However, surface visibilities should improve somewhat Friday before falling again to IFR with rain and fog late Friday into Saturday morning. This occurs as a low level NE flow strengthens out ahead of an approaching storm system from the SW Friday night. This storm is expected to lift N of the region Saturday afternoon. The outlook for Saturday late through Sunday is for improving aviation conditions as the widespread rain/fog move north of the region between 12z-18z Saturday. VFR conditions are expected Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...WSS LONG TERM...KRD AVIATION...Badgett
  [top] Area Forecast Discussion National Weather Service Wilmington NC 933 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build from the north overnight into Thursday. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 933 PM Wednesday...No significant changes required with the middle evening updates as mostly cloudy skies prevail with local temperatures overnight very close to climatology for this time of May. No drivers for significant PCPN tonight aside from MCV perturbation showers west of I-95 after 2 AM. Low-level saturation late tonight may materialize a patch or 2 of drizzle, but for most locations, measurable rainfall is not likely. With low cloud ceilings and nearly saturated low level air, temperature drops will be slow to evolve, settling in the upper 50s to lower 60s daybreak Thursday. A pocket of mist or fog cannot be ruled out overnight as well given the very damp regime in place near the surface. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... As of 00Z...MVFR with brief improvement to VFR possible this evening before widespread MVFR/IFR returns with areas of fog possible overnight. Improvement to VFR on Thursday is expected with increasing chances for showers throughout the day. Though latest radar imagery remains fairly quiet this evening, satellite imagery continues to show broken to overcast coverage of low clouds allowing for widespread MVFR to prevail at the terminals. Trends do indicate the potential for brief improvement to VFR over the next few hours, before cloud coverage increases again overnight. This along with developing areas of fog will create MVFR/IFR through the early morning hours. Light and variable winds are expected. After daybreak, expect conditions to improve to VFR with increasing chances for showers into the afternoon hours. Northeasterly winds around 5 kts in the morning will become east-northeasterly in the afternoon around around 10 kts. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 933 PM Wednesday...`Exercise Caution" headline is needed for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly mellower wind-speeds over the SC waters precludes this headline. Caution headline valid until midnight tonight as wind trends ease this evening, as a low offshore of Cape Lookout moves NE away from the coast...thus a very brief cautionary period. Virtually no wave energy with wave periods greater than 7 seconds exists right now and all energy is tied to nearby winds...thus slightly steep and bumpy this evening for only 3-5 ft seas. Dominant wave periods will hold between 6-7 seconds overnight with little or no shower activity. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MJC SHORT TERM...DCH LONG TERM...III AVIATION...SGL
  [top] Area Forecast Discussion National Weather Service Newport/Morehead City NC 837 PM EDT WED MAY 18 2016 .SYNOPSIS... Low pressure off the coast will continue to move northeast away from the area tonight. High pressure will extend into the area from the north Thursday and Friday. Low pressure will develop to the southwest late Friday night then lift northeast across the region Saturday. The low will lift northeast of the area Saturday night and Sunday pushing a cold front offshore. Low pressure will develop well offshore early next week as high pressure builds south of the region. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 730 PM Wednesday...Updated to indicate some clearing over northern sections this evening per latest obs/satellite trends. Still expect some lower cloudiness to develop...thus kept mostly cloudy/cloudy forecast for overnight. Minor adjustments for latest hourly temp/dew point trends. /Previous discussion/ As of 230 PM Wednesday...Rain has rapidly diminished across the region and will lower pops to slight chc thru early evening with patchy light rain or drizzle...mainly near coast. Any lingering precip should end by mid evening as drier mid level air spreads in. Low levels will remain nearly saturated and expect good deal of clouds to persist thru the night. Lows will be mainly in the mid to upper 50s...poss holding around 60 central/southern beaches. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... As of 230 PM Wednesday...High pressure will build N of the area with mainly dry weather expected. Bulk of models do show some increase in moisture and light qpf SW tier late ahead of weak short wave so added slight pop this area. Plenty of clouds will continue over the region and with NNE surface flow temps will remain cool with highs low/mid 70s with some 60s Outer Banks. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As of 3 pm Wednesday...A very active weather pattern with below normal temps through a portion of the period. Thursday Night through Friday Night: High pressure will migrate eastward through the Mid-Atlantic states during the period, eventually moving offshore by early Saturday. North flow will start to veer easterly Friday as the surface high shifts offshore. Southeast flow increases Friday night as the next storm system approaches from the southwest. Introduced slight chance pops Thursday night into Friday for the southerly third of the CWA as a weak boundary remains south of the area with moisture lingering. PWATS increase rapidly Friday afternoon/evening as southwesterly flow in the mid levels brings in greater moisture across the area. Precip chances increase from slight chance late Friday to likelies late Friday night, partly due to a warm front lifting north through the region. Temps Friday will range low/mid 70s due to precip/clouds. Thursday night lows will range in the mid 50s to near 60 along the OBX, and mid/upper 60s areawide on Friday night. Saturday through Monday: A developing surface low will shift northeast through Eastern NC on Saturday as an upper trough digs southeast from the Great Lakes into the Mid-Atlantic region. This will result in a surface low developing/moving north of the area Saturday with a cold front crossing Saturday afternoon/evening. Given we will be under the warm sector ahead of the front with ample lift, moisture and sufficient instability/shear, the convective potential looks probable, especially in the afternoon. The timing of this front and the subsequent cloud cover will be a big factor in the severity/coverage of any storms that develop. It is a bit far out to iron out details at this point, but looks like the front crossing around late afternoon will limit convection in the evening. The surface low will move off the Mid- Atlantic coast Sunday with the closed upper low becoming anchored across the Eastern CONUS through midweek. This will then provide continued cloud cover and slight chance showers through the remainder of the period. Temps will remain in the low/mid 70s during this period, with the cooler day being Sunday after the front crosses and a surge of cooler air moves into the region. Tuesday through Wednesday: The closed upper low will finally lift northeast into New England with zonal flow developing by Wednesday. Meanwhile, high pressure quickly builds in, shifting offshore by Wednesday ushering in warm return flow and more seasonable temperatures. High temps Tuesday will be in the upper 70s and rebound into the low/mid 80s by Wednesday. Given moisture return and modest instability, introduced slight chance showers and thunderstorms for Wednesday afternoon for inland sections. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... Short Term /Through 00Z Friday/... As of 730 PM Wednesday...Problematic forecast for this evening as guidance is not in good agreement with latest obs trends. Most of guidance indicatest current mainly MVFR cigs lowering to IFR by late evening with IFR/LIFR then persisting into Thursday morning. However obs and satellite indicate clearing moving into NW sections as slightly drier air mass is advecting in as low pressure moves offshore. Have gone with obs trend next few hours...but with diminishing winds and moist low levels...still expect some IFR stratus to develop 03Z-06z and persist into morning. Cigs will improve to VFR by 15Z...but some increased lift may result in MVFR cigs again after 21Z. Forecast confidence moderate at best. Long Term /Thursday Night through Monday/... As of 310 pm Wednesday...High pressure to the north will persist through Friday, then eventually shifts offshore Friday Night. Expect VFR conditions through Friday, with some mid level clouds returning Thursday night through Friday especially for OAJ/EWN. With return flow quickly developing Friday afternoon and the increase in precipitation, expect lowering ceilings with sub-VFR conditions likely. Ample moisture will be present Friday night through much of Saturday ahead of a front that is progged to cross later Saturday. Lingering sub-VFR conditions can be expected early Sunday. Drier air will work its way into the region through the remainder of Sunday and into Monday. However, do expect lingering mid/upper level clouds Sunday under north flow. Predominant VFR expected Monday. && .MARINE... Short Term /Tonight and Thursday/... As of 730 PM Wednesday...No changes with update. /Previous discussion/ As of 230 PM Wednesday...NNE winds remain quite gusty along the coast to N and W of low pressure located SE of Cape Lookout. Winds should remain up along the coast into the evening before diminishing overnight as low departs. Seas of 5 to 8 feet will continue over the coastal waters into this evening. Later tonight as the low moves further offshore winds will gradually diminish and seas are expected to subside below 6 feet by early Thursday morning. NNE winds will cont at 10 to 15 knots Thu with some gusts to around 20 knots northern and central waters as high pressure builds north of the area. Seas will be mainly 3 to 5 feet Thursday...quite a bit lower over waters near the coast south of Cape Lookout. Long Term /Thursday Night through Monday/... As of 320 pm Wednesday...High pressure will build across the waters from the north Thursday night into Friday, moving offshore late Friday ahead of the next storm system. Southeast winds will quickly increase Saturday ahead of a cold front set to cross the waters Saturday Night/early Sunday. Winds expected to be around 15-25kts with higher gusts. Seas will build by Saturday afternoon, to around 6 to 8 feet across the central waters. Behind the front, winds shift northwesterly Saturday night into early Sunday with wind speeds 10-20 kts, helping to maintain seas 4 to 6 feet across the northern waters through late Saturday night. Winds shift northerly Monday but continue mostly 5-15 kt, yielding seas 3-5 ft north to 2-4 ft south. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 2 AM EDT Thursday for AMZ135-150- 156-158. Small Craft Advisory until 6 AM EDT Thursday for AMZ152-154. && $$ SYNOPSIS...RF NEAR TERM...RF/JBM SHORT TERM...RF LONG TERM...DAG/LEP AVIATION...JBM/DAG/SGK MARINE...RF/JBM/DAG
Area Forecast Discussion National Weather Service Raleigh NC 750 PM EDT Wed May 18 2016 .SYNOPSIS...In the wake of a departing low pressure system...a cool surface high pressure system will build over the area tonight through Thursday. A low pressure system tracking east across the Southern states will bring wet unsettled conditions to the Carolinas late Friday through early Saturday. && .NEAR TERM /through tonight/... As of 330 PM Wednesday... A sfc wave continues to linger off the SE coast of NC this afternoon. This feature will drift farther offshore tonight...being pushed along by a s/w in the northern stream crossing southern new england. In its wake...a weak shear axis and attendant inverted sfc trough will drift east into western NC tonight/early Thu. This feature interacting with abundant low level moisture may trigger a few showers in the vicinity of the Yadkin River late this evening through the overnight. Widespread cloud cover will limit the normal nocturnal cooling. Min temps low-mid 50s north half with upper 50s south. && .SHORT TERM /Thursday and Thursday night/... As of 330 PM Wednesday... WRF models along with a few near term models have trended wetter than previous runs for Thursday...apparently keying on the weak shear axis and inverted sfc trough. The WRF models are likely overdone considering they are overplaying the rain showers this afternoon in vicinity of the higher terrain in western NC. While the GFS and ECMWF both depict the inverted sfc trough washing out...being replaced by a narrow ridge of high pressure...model guidance still depicting measurable rain over most of central NC on Thursday. Models may be keying on confluence along a west-to-east 850mb boundary in vicinity of highway 64. Cross sections, however, reveal that the lift, weak as it is, is confined to the lowest 8k ft or so of the atmosphere. Thus, having a tough time buying into the high end likely/low end categorical pops across the area for Thursday. Appears highest threat for measurable rain will be Thursday morning...and mainly confined to the far SW. After 16Z, rain chances should be no more than a chance and highest over the south. Extensive cloud cover and chances for precip will prevent temps from warming much above overnight low temps. High temps should vary from the low-mid 60s north to the lower 70s se. If rain is more extensive than forecast, high temp may end up being 3-5 degrees cooler. Weak isentropic upglide late Thursday night will yield spots of light rain...especially after 04Z and mainly over the sw third of the forecast area. Min temps generally in the mid-upper 50s. && .LONG TERM /Friday through Wednesday/... As of 230 PM Wednesday... Friday through Saturday: High pressure will be extending down the east coast to begin the long term period, with a cold air damming regime setting up over the region. At the same time, a short wave will be moving towards the area from the west and this will set the stage for a rather wet period. A couple of waves of low pressure are progged to track near/along the CAD boundary that will set up across the area. Precip chances will increase from west to east throughout the day on Friday, with the best time frame being Friday night/early Saturday morning. Given the high shear/low cape environment that is expected, the severe weather threat is expected to be rather low, especially given the poor diurnal timing. The bigger threat is going to be the heavy rain potential, where average rainfall amounts are expected to range from around an inch across the southeast to possibly around 2 inches or more across the Northwest Piedmont, which could cause some minor flooding in urban areas or poor drainage locations. The majority of the precip should shift off to the northeast throughout the afternoon on Saturday, although persistent cyclonic flow aloft will linger across the area and will result in mostly cloudy skies and possibly a lingering showers into Saturday night. Given the CAD regime, high temps should range from low/mid 70s across the southeast to the low/mid 60s across the northwest. Sunday through Wednesday: Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /00Z Thursday through Monday/... As of 750 PM Wednesday... Poor aviation conditions will continue overnight as low clouds persist in northeasterly flow. The areawide improvement to MVFR this afternoon should give way to at least IFR by 06z, with some lifr and rain/drizzle possible at KGSO and KINT by 12z. The light rain and drizzle is expected to shift east through the morning hours, though with some drier low-level air filtering in from the northeast, confidence in the coverage of precip is lower toward KRDU and KRWI. There should be some slow improvement of ceilings in the east by midday, to MVFR and possibly VFR at KFAY by Thursday evening. Abundant moisture will continue the threat of low ceilings through Friday night. A strong low pressure system and cold front will cross the region on Saturday, helping to scour low-level moisture and bring VFR conditions for Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...WSS LONG TERM...KRD AVIATION...22
Area Forecast Discussion National Weather Service Wilmington NC 756 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build from the north overnight into Thursday. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 704 PM Wednesday...No significant changes required with the early evening updates as mostly cloudy skies prevail with local temperatures overnight very close to climatology for this time of May. No drivers for significant PCPN tonight aside from MCV perturbation showers west of I-95 after 3 AM. Low level saturation late tonight may materialize a patch or 2 of drizzle, but for most locations, measurable rainfall is not likely. With low cloud ceilings and nearly saturated low level air, temperature drops will be slow to evolve, settling in the upper 50s to lower 60s daybreak Thursday. A pocket of mist or fog cannot be ruled out overnight as well given the very damp regime in place near the surface. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 00Z...MVFR with brief improvement to VFR possible this evening before widespread MVFR/IFR returns with areas of fog possible overnight. Improvement to VFR on Thursday is expected with increasing chances for showers throughout the day. Though latest radar imagery remains fairly quiet this evening, satellite imagery continues to show broken to overcast coverage of low clouds allowing for widespread MVFR to prevail at the terminals. Trends do indicate the potential for brief improvement to VFR over the next few hours, before cloud coverage increases again overnight. This along with developing areas of fog will create MVFR/IFR through the early morning hours. Light and variable winds are expected. After daybreak, expect conditions to improve to VFR with increasing chances for showers into the afternoon hours. Northeasterly winds around 5 kts in the morning will become east-northeasterly in the afternoon around around 10 kts. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 704 PM Wednesday...`Exercise Caution" headline is needed for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly mellower wind-speeds over the SC waters precludes this headline. Caution headline valid until midnight tonight as wind trends ease this evening, as a low offshore of Cape Lookout moves NE away from the coast...thus a very brief cautionary period. Virtually no wave energy with wave periods greater than 7 seconds exists right now and all energy is tied to nearby winds...thus slightly steep and bumpy this evening for only 3-5 ft seas. Dominant wave periods will hold between 6-7 seconds overnight with little or no shower activity. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MJC SHORT TERM...DCH LONG TERM...III AVIATION...SGL
Area Forecast Discussion National Weather Service Wilmington NC 704 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build from the north overnight into Thursday. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 704 PM Wednesday...No significant changes required with the early evening updates as mostly cloudy skies prevail with local temperatures overnight very close to climatology for this time of May. No drivers for significant PCPN tonight aside from MCV perturbation showers west of I-95 after 3 AM. Low level saturation late tonight may materialize a patch or 2 of drizzle, but for most locations, measurable rainfall is not likely. With low cloud ceilings and nearly saturated low level air, temperature drops will be slow to evolve, settling in the upper 50s to lower 60s daybreak Thursday. A pocket of mist or fog cannot be ruled out overnight as well given the very damp regime in place near the surface. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 18Z... Low clouds will be persistent through the period. However through the afternoon they may tend to occasionally break from IFR to MVFR. With the loss of daytime heating lower ceilings will become more favorable, though not all model guidance indicates such. Have opted to keep with the more pessimistic view which does in fact sock the area in with IFR overnight and show improvement to MVFR a few hours after daybreak Thursday. Any visibility restrictions will be minor, MVFR-ish. Little to no precipitation is expected. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 704 PM Wednesday...`Exercise Caution" headline is needed for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly mellower wind-speeds over the SC waters precludes this headline. Caution headline valid until midnight tonight as wind trends ease this evening, as a low offshore of Cape Lookout moves NE away from the coast...thus a very brief cautionary period. Virtually no wave energy with wave periods greater than 7 seconds exists right now and all energy is tied to nearby winds...thus slightly steep and bumpy this evening for only 3-5 ft seas. Dominant wave periods will hold between 6-7 seconds overnight with little or no shower activity. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MJC SHORT TERM...DCH LONG TERM...III AVIATION...SGL
Area Forecast Discussion National Weather Service Wilmington NC 337 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build in from the north overnight. A stalled front will move north across the area Friday as a warm front. A surface low will pass over or just west of the area late Friday night and drag a cold front across the area Saturday. Showers and thunderstorms are likely ahead of the front. Clouds and showers may linger on Sunday under low pressure aloft. The low will slowly move away from the area Monday through Wednesday with dry and seasonable conditions returning by the middle of next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 3 PM Wednesday...Models are in a decent consensus with sfc ridging from the north dominating thru early fri, with the highs center moving from the great lakes on Thu, to the NE States by early Fri. For Fri thru Fri night is when models detour from one another with respect to the eventual inland movement of the coastal front. Some mid and upper level drying early Thu will slowly moisten thruout the atm column by late Thu. Overrunning type pcpn will begin mid to late day Thu and persist thru Thu night into daytime Fri. some timing issues will exist afterwards from Fri aftn thru Fri night with regard to the coastal front lifting inland and eventually northward across the ilm cwa. Thu thru early Fri pcpn will be limited to mainly overrunning type pcpn with embedded heavier showers possible. Any thunder will remain south and east of the ILM CWA closer to where the frontal boundary lies and to where it bends inland over southern SC. For daytime Fri thru Fri night...the ILM CWA will be subject to heavier pcpn with overrunning light showers/rain dominating initially. As the coastal front pushes inland and at the same time lifting northward, the fa will find itself in the warm sector by daybreak sat. thus, convective type pcpn will eventually become the dominant type. this will also be reflected within the qpf fields. Stayed with a consensus of available model mos guidance thru daytime Fri...which basically keeps mid to upper 70s for highs, and upper 50s inland to low 60s at the coast for lows. For Fri night, the fa will see widespread 60s to near 70 at the coast for Sat lows. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... As of 18Z... Low clouds will be persistent through the period. However through the afternoon they may tend to occasionally break from IFR to MVFR. With the loss of daytime heating lower ceilings will become more favorable, though not all model guidance indicates such. Have opted to keep with the more pessimistic view which does in fact sock the area in with IFR overnight and show improvement to MVFR a few hours after daybreak Thursday. Any visibility restrictions will be minor, MVFR-ish. Little to no precipitation is expected. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes Thursday morning will push east to the NE States by Fri, and off the NE States Coast Fri night. Sfc ridging from the highs center will extend south/down the east coast. at the same time, a stalled frontal boundary or coastal front will lie just offshore and parallel to the ILM CWA coastline, before bending back westward and inland in the vicinity of the SC and GA Border. As a result, the local waters will be subject to a ne-ene wind direction thru early Fri. A somewhat tightened sfc pg will exist thruout the period, with wind speeds generally in the 10 to 20 kt range. From midday Fri thru Fri night...the frontal boundary offshore and south of the area waters...will push inland and lift northward at the same time. This boundary is expected to push inland during Fri night with winds veering from the e to se Fri Evening...and further veering to the South by daybreak Sat. Wind speeds will remain 10 to 20 kt especially after the front pushes onshore. Significant seas will mainly be a function of wind driven waves, with dominating periods increasing from 4 to 5 seconds early Thu to 6 to 7 seconds on Fri. Sea Heights will likely reach SCEC Thresholds Thu Night, and possibly SCA Thresholds during Fri. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...DCH SHORT TERM...DCH LONG TERM...III AVIATION...MBB
Area Forecast Discussion National Weather Service Newport/Morehead City NC 324 PM EDT WED MAY 18 2016 .SYNOPSIS... Low pressure off the coast will continue to move northeast away from the area tonight. High pressure will extend into the area from the north Thursday and Friday. Low pressure will develop to the southwest late Friday night then lift northeast across the region Saturday. The low will lift northeast of the area Saturday night and Sunday pushing a cold front offshore. Low pressure will develop well offshore early next week as high pressure builds south of the region. && .NEAR TERM /THROUGH TONIGHT/... As of 230 PM Wednesday...Rain has rapidly diminished across the region and will lower pops to slight chc thru early evening with patchy light rain or drizzle...mainly near coast. Any lingering precip should end by mid evening as drier mid level air spreads in. Low levels will remain nearly saturated and expect good deal of clouds to persist thru the night. Lows will be mainly in the mid to upper 50s...poss holding around 60 central/southern beaches. && .SHORT TERM /THURSDAY/... As of 230 PM Wednesday...High pressure will build N of the area with mainly dry weather expected. Bulk of models do show some increase in moisture and light qpf SW tier late ahead of weak short wave so added slight pop this area. Plenty of clouds will continue over the region and with NNE surface flow temps will remain cool with highs low/mid 70s with some 60s Outer Banks. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As of 3 pm Wednesday...A very active weather pattern with below normal temps through a portion of the period. Thursday Night through Friday Night: High pressure will migrate eastward through the Mid-Atlantic states during the period, eventually moving offshore by early Saturday. North flow will start to veer easterly Friday as the surface high shifts offshore. Southeast flow increases Friday night as the next storm system approaches from the southwest. Introduced slight chance pops Thursday night into Friday for the southerly third of the CWA as a weak boundary remains south of the area with moisture lingering. PWATS increase rapidly Friday afternoon/evening as southwesterly flow in the mid levels brings in greater moisture across the area. Precip chances increase from slight chance late Friday to likelies late Friday night, partly due to a warm front lifting north through the region. Temps Friday will range low/mid 70s due to precip/clouds. Thursday night lows will range in the mid 50s to near 60 along the OBX, and mid/upper 60s areawide on Friday night. Saturday through Monday: A developing surface low will shift northeast through Eastern NC on Saturday as an upper trough digs southeast from the Great Lakes into the Mid-Atlantic region. This will result in a surface low developing/moving north of the area Saturday with a cold front crossing Saturday afternoon/evening. Given we will be under the warm sector ahead of the front with ample lift, moisture and sufficient instability/shear, the convective potential looks probable, especially in the afternoon. The timing of this front and the subsequent cloud cover will be a big factor in the severity/coverage of any storms that develop. It is a bit far out to iron out details at this point, but looks like the front crossing around late afternoon will limit convection in the evening. The surface low will move off the Mid- Atlantic coast Sunday with the closed upper low becoming anchored across the Eastern CONUS through midweek. This will then provide continued cloud cover and slight chance showers through the remainder of the period. Temps will remain in the low/mid 70s during this period, with the cooler day being Sunday after the front crosses and a surge of cooler air moves into the region. Tuesday through Wednesday: The closed upper low will finally lift northeast into New England with zonal flow developing by Wednesday. Meanwhile, high pressure quickly builds in, shifting offshore by Wednesday ushering in warm return flow and more seasonable temperatures. High temps Tuesday will be in the upper 70s and rebound into the low/mid 80s by Wednesday. Given moisture return and modest instability, introduced slight chance showers and thunderstorms for Wednesday afternoon for inland sections. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... Short Term /Through Thursday Afternoon/... As of 145 pm Wed...IFR conditions are present across the region due to ceilings just under 1000 feet. Expecting ceilings to rise another couple hundred feet this afternoon...which will raise conditions to MVFR. However IFR ceilings will return after or near midnight with continued northeast flow and trapped low level moisture. LIFR conditions could be met early Thursday morning but will hold off on mentioning them in the TAF for this issuance. Fog looks unlikely due to a lingering light breeze overnight but patchy fog cannot be ruled out. VFR conditions should return after 8 or 9 am Thursday under continued cloudy skies. Long Term /Thursday Night through Monday/... As of 310 pm Wednesday...High pressure to the north will persist through Friday, then eventually shifts offshore Friday Night. Expect VFR conditions through Friday, with some mid level clouds returning Thursday night through Friday especially for OAJ/EWN. With return flow quickly developing Friday afternoon and the increase in precipitation, expect lowering ceilings with sub-VFR conditions likely. Ample moisture will be present Friday night through much of Saturday ahead of a front that is progged to cross later Saturday. Lingering sub-VFR conditions can be expected early Sunday. Drier air will work its way into the region through the remainder of Sunday and into Monday. However, do expect lingering mid/upper level clouds Sunday under north flow. Predominant VFR expected Monday. && .MARINE... Short Term /Tonight and Thursday/... As of 230 PM Wednesday...NNE winds remain quite gusty along the coast to N and W of low pressure located SE of Cape Lookout. Winds should remain up along the coast into the evening before diminishing overnight as low departs. Seas of 5 to 8 feet will continue over the coastal waters into this evening. Later tonight as the low moves further offshore winds will gradually diminish and seas are expected to subside below 6 feet by early Thursday morning. NNE winds will cont at 10 to 15 knots Thu with some gusts to around 20 knots northern and central waters as high pressure builds north of the area. Seas will be mainly 3 to 5 feet Thursday...quite a bit lower over waters near the coast south of Cape Lookout. Long Term /Thursday Night through Monday/... As of 320 pm Wednesday...High pressure will build across the waters from the north Thursday night into Friday, moving offshore late Friday ahead of the next storm system. Southeast winds will quickly increase Saturday ahead of a cold front set to cross the waters Saturday Night/early Sunday. Winds expected to be around 15-25kts with higher gusts. Seas will build by Saturday afternoon, to around 6 to 8 feet across the central waters. Behind the front, winds shift northwesterly Saturday night into early Sunday with wind speeds 10-20 kts, helping to maintain seas 4 to 6 feet across the northern waters through late Saturday night. Winds shift northerly Monday but continue mostly 5-15 kt, yielding seas 3-5 ft north to 2-4 ft south. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 2 AM EDT Thursday for AMZ135-150- 156-158. Small Craft Advisory until 6 AM EDT Thursday for AMZ152-154. && $$ SYNOPSIS...RF NEAR TERM...RF SHORT TERM...RF LONG TERM...DAG/LEP AVIATION...DAG/SGK MARINE...RF/DAG
Area Forecast Discussion National Weather Service Raleigh NC 237 PM EDT Wed May 18 2016 .SYNOPSIS...In the wake of a departing low pressure system...a cool surface high pressure system will build over the area tonight through Thursday. A low pressure system tracking east across the Southern states will bring wet unsettled conditions to the Carolinas late Friday through early Saturday. && .NEAR TERM /through tonight/... As of 1030 AM Wednesday... Upper air analysis depict a weak low level trough over the ne sector of central NC. Weak confluence along this boundary in conjunction with modest lift aloft associated with divergence in the right entrance region of a 110+ kt jet exiting the northern Mid-Atlantic was causing spots of light rain/drizzle across sections of central NC this morning. The patches of light rain/drizzle will diminish with time and lift becomes weaker. Abundant low level moisture will be tough to scour out due to lack of sufficient mixing of drier air...thus a blanket of low stratus will persist into the afternoon hours. Area MDCRS aircraft soundings suggest the cloud thickness about a 1000ft or a little less. This suggest that some breaks may occur late in the day...though likely too late to add in temp recovery. Low overcast skies and a steady near sfc ne wind will hold temps well below normal for mid-May. Afternoon temps will top out in the mid-upper 60s north to near 70-lower 70s south. -WSS Ceilings are expected to quickly fall/lower after sunset with IFR to LIFR conditions expected everywhere overnight. Continued weak upglide along the eastern slopes of the mtns will continue to support a slight to small chance of rain, mainly across the western Piedmont. Lows tonight in the lower 50s north to upper 50s south. -CBL && .SHORT TERM /Thursday and Thursday night/... As of 345 AM Wednesday... Parent high center will build over the Mid-Atlantic Seaboard on Thursday with low-level wedge of cooler and drier air ridging south into the area underneath continued WSW flow aloft, within the right entrance region of a ~90kt upper jet streak in place over the Mid- Atlantic region. Low clouds/moisture will persist but sufficient forcing is absent over the area during the day on Thursday. So expect a gray gloomy day across the area with continued below normal temperatures in the mid/upper 60s north to lower 70s south. Weak upglide begins to strengthen Thursday night, in response to mid- level shortwave trough and sfc cyclogenesis over the lower MS/TN Valleys. Better rain chances will remain to our west but will continue to indicate isolated/slight chance pops across the far southern/southwestern zones with onset of In-situ Damming expected. Lows again in the lower 50s to upper 50s, coolest ne. && .LONG TERM /Friday through Wednesday/... As of 230 PM Wednesday... Friday through Saturday: High pressure will be extending down the east coast to begin the long term period, with a cold air damming regime setting up over the region. At the same time, a short wave will be moving towards the area from the west and this will set the stage for a rather wet period. A couple of waves of low pressure are progged to track near/along the CAD boundary that will set up across the area. Precip chances will increase from west to east throughout the day on Friday, with the best time frame being Friday night/early Saturday morning. Given the high shear/low cape environment that is expected, the severe weather threat is expected to be rather low, especially given the poor diurnal timing. The bigger threat is going to be the heavy rain potential, where average rainfall amounts are expected to range from around an inch across the southeast to possibly around 2 inches or more across the Northwest Piedmont, which could cause some minor flooding in urban areas or poor drainage locations. The majority of the precip should shift off to the northeast throughout the afternoon on Saturday, although persistent cyclonic flow aloft will linger across the area and will result in mostly cloudy skies and possibly a lingering showers into Saturday night. Given the CAD regime, high temps should range from low/mid 70s across the southeast to the low/mid 60s across the northwest. Sunday through Wednesday: Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /18Z Wednesday through Monday/... As of 120 pm Wednesday... There is a high likelihood that mvfr/ifr ceilings will persist across central NC through tonight. In addition, there will be pockets of mvfr/ifr fog developing after 05Z. Spots of light rain will be possible in vicinity of the Triad terminals toward daybreak...possibly heading into the KRDU vicinity by mid morning. Abundant low level moisture will maintain a deck of low clouds across central NC through early friday...and possibly through Saturday morning. A pair of weak low pressure systems will increase the threat for rain showers across central NC. The initial wave will bring an enhanced threat for showers late Thursday night to the southern counties including the KFAY vicinity. The later wave...forecast to be stronger...will increase the threat for showers across most of central NC Friday night into Saturday morning. Improving aviation conditions are expected by late Saturday...with a good probability of vfr conditions Sunday and Monday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...wss NEAR TERM...WSS/CBL SHORT TERM...CBL LONG TERM...KRD AVIATION...wss Area Forecast Discussion National Weather Service Raleigh NC 1025 AM EDT Thu May 19 2016 .SYNOPSIS...An upper level disturbance will push across the region today. A weak and cool surface high pressure will continue to extend into central North Carolina through Friday. A much stronger storm system is expected to move into the region late Friday into early Saturday. && .NEAR TERM /through tonight/... As of 1025 AM Thursday... Patches of light rain this morning a result of a nearly saturated atmosphere in the lowest 15k ft and decent speed convergence in the 700-500mb layer. Rain coverage expected to increase in coverage and intensity by mid day through the afternoon hours across the southern counties as a well defined vort max crosses to our south. Expect spotty light rain north of highway 64 through the afternoon. The patches/areas of light rain...widespread overcast skies...and a steady ne sfc flow will prevent temps from recovering too much from their current levels. High temps today should vary from the upper 50s nw to the mid/upper 60s se. -WSS Significant rain chances lower tonight in the rear of the upper disturbance departing to the NE. However, the low overcast conditions should continue tonight enhanced by the low level NNE flow. In fact, the main chilly surface high pressure is forecast to move east to PA later tonight. The high is of sufficient strength and in a proper position to deliver additional cool stable air into the region to allow for the persistence of the CAD, then enhancement of the CAD Friday into Friday night as the next storm approaches from the SW (see discussion below). Lows tonight 50s except lower 60s SE. -Badgett && .SHORT TERM /Friday through Saturday/... As of 258 AM Thursday... Issues ahead for Friday through Saturday will be mainly with the rainfall forecasts and the continued very cool temperatures for daily highs through at least Saturday. Any severe threat associated with the approaching storm system late Friday and Friday night have essentially been erased by the agreement of the models with hybrid CAD over our region and by the forecast of the storm track to be up along or east of I-95 late Friday night and early Saturday. This storm track is more of a Miller B with one low lifting NE through the TN and OH valley as another develops along the SC/NC coastal area late Friday night, then tracks up the coast Saturday. This pattern has a cool stable and almost "wintry" look to it. To begin Friday, a very cool surface high pressure is forecast to be centered over PA. The strength is expected to be around 1025 MB. The location and strength are both sufficient to deliver additional cool stable air into central NC from the north Friday. This occurs as the initial low pressure is forecast to track NE into the TN valley region by late Friday. All of our region is expected to be dominated by the cool stable low level high to the north. As such, temperatures Friday will be hard pressed to get out of the 60s anywhere in the region. Some upper 50s may again linger around the Triad to Roxboro in the continued hybrid CAD resume. The CAD will be strengthen as the day goes on as a cool stable NE flow pumps into the damming region of the Piedmont. Models suggest that some areas of light rain may develop/overspread portions of the Piedmont during the afternoon before widespread rain arrives Friday night. Even though the parent surface high will move offshore of New England Friday, the cool stable dome will have already been enhanced and firmly established. The coastal front is forecast to be pinned at the immediate coast. As one storm lifts NE toward the central Appalachians, another one will develop and take over near the boundary along the SC coast Friday night. This low will then lift NE along the coast early Saturday. There will be very little chance in this scenario of the coastal front being pulled inland, thus eliminating the severe risk over our region. However, a few elevated thunderstorms are expected to be embedded in the large rain area that overspreads the region Friday night, then ends from the southwest Saturday morning. The storm will then lift away from the region Saturday afternoon with dramatically lowering POP. However... the northerly flow behind the system along with lingering moisture in the low levels should keep any partial clearing confined to the SW Piedmont Saturday afternoon. Highs will be held down again by the residual CAD and then the persistent northerly flow as the storm pulls away. Expect readings to be warmest where any breaks occur in the SW Piedmont (possibly near 70). Most areas will stay in the lower to mid 60s (which is a good 20 degrees below normal). QPF will continue to be a tough call given the complexity of the evolving storm and the hybrid CAD over inland areas. Not to mention the deep south/Gulf coast convection potential. Even though models continue to be generous with 1 to locally 1.5 inches, this may be overdone in some areas. Flash flooding is not anticipated with the lack of strong convection and with the FFG values running rather high in the 3+ inch range in 6 hours. This is not expected to be threatened. But 1 to 1.5 inches in 6 hours may result in some minor flooding in urban and flood prone areas. && .LONG TERM /Saturday night through Wednesday/... As of 3 AM Thursday... Additional energy is expected to dive southward out of Canada helping to close off into a mid/upper level low along the mid atlantic coast late weekend into early next week, which will result in continue chances for showers and possibly some storms depending on the placement of the mid/upper low for Sunday and Monday (chance of convection everywhere for Sunday and limited to just eastern portions of the area my Monday). However, the best chance for precip will be during the afternoon into the evening/more diurnally driven convection. Highs Sunday and Monday are expected to remaining below normal in the 70s. Highs Tuesday and Wednesday will return to more seasonable values as the mid/upper low is expected to lift off to the northeast and surface high pressure is expected to shift offshore finally. Lows temps are expected to be near to slightly below normal for the medium range. && .AVIATION /12Z Thursday through Monday/... As of 700 AM Thursday... Low ceilings and occasionally low visibilities as well will persist today and tonight. Occasional rain and drizzle can be expected in the region along with persistent MVFR becoming IFR CIGS at or below 1K feet today. Abundant moisture will continue the low ceilings through tonight and into Friday. However, surface visibilities should improve somewhat Friday before falling again to IFR with rain and fog late Friday into Saturday morning. This occurs as a low level NE flow strengthens out ahead of an approaching storm system from the SW Friday night. This storm is expected to lift N of the region Saturday afternoon. The outlook for Saturday late through Sunday is for improving aviation conditions as the widespread rain/fog move north of the region between 12z-18z Saturday. VFR conditions are expected Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...WSS/Badgett SHORT TERM...Badgett/BSD LONG TERM...BSD AVIATION...Badgett
  [top] Area Forecast Discussion National Weather Service Wilmington NC 1005 AM EDT THU MAY 19 2016 .SYNOPSIS... High pressure will build from the north today. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /THROUGH TONIGHT/... As of 10 am Thursday...Showers detached/not rooted at the surface but above the stable boundary layer and low levels will track ENE near I-95. The rainfall is mainly anvil -ra and qpf potential remains low and confined across far interior locations. this light rain will progress but struggle across the northern inland tier of SE NC...as the impulse-induced showers encounter increasingly stable low level air...eating away a bit at the rain cores. The short-wave presently over Georgia triggering +TSRA will likely impact the coast and coastal interior of NE SC and SE NC late today and tonight. This feature will help bump a warm frontal boundary slightly northward into NE SC and SE NC by 00z...upping prospects of rainfall...as boundary layer to h8 ascent is generated. Tricky maximum temperature forecast today but no significant adjustments needed yet as cooler air prevails beneath expected rainfall locals with more sunny breaks and insolation unfolding over the NE-E zones. After an initial drop in temps occur this evening...readings will likely level off after 3z-4z in a 59-65 degree range holding into daybreak...mildest near the sea. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 315 am Thursday...The main feature of note in the Friday- Saturday portion of the forecast is an impressive upper level disturbance expected to roll eastward from the lower Mississippi Valley across the Carolinas Friday night, then offshore Saturday afternoon. A surface wave of low pressure will develop along a warm front across Georgia and southern Carolina early Friday, bowing northward into southeastern North Carolina late Friday night into early Saturday. As the low exits the North Carolina coast Saturday the front will be pushed southward and offshore. The best synoptic lift should occur late Friday night into Saturday morning when my forecast POPs are in the 70-80 percent range with QPF 0.5 to 1.0 inches. Given the time of day the risk for severe weather appears minimal, however thunderstorms certainly remain in the forecast given sufficiently steep mid-level lapse rates. A model blend, heavy on the GFS, has been used for temperatures through the period. There is larger than normal uncertainly with regard to high temperatures on Saturday. Recent model trends have shown a much quicker clearing trend developing with this morning`s 00z models now suggesting there could be a good deal of sunshine Saturday afternoon, especially across South Carolina. While a couple of days ago we were anticipating plenty of clouds to hang in with northerly surface winds, this new idea could lead to temperatures soaring much higher than originally anticipated. We`ll see what the next round of models do with this Saturday clearing before making large adjustments to the forecast. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 315 am Thursday...Highly amplified pattern will relax somewhat by the latter part of next week. Initially a deep mid level trough will linger over the Delmarva region before getting kicked out Monday. Overall trends for pops have decreased beyond Sunday when a few showers may develop with the feature. The broad southwest flow that develops may bring in some moisture late in the period as surface high pressure moves offshore. A little too early to add any mention of pops as the system is very diffuse at this point. Temperature guidance points to a steady warming trend through the period with climatological normals by the end of the period. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... As of 12Z...Weak surface high pressure is located over the terminals this morning. This is resulting in light NE winds at the coast and light E winds inland. LIFR/IFR conditions are affecting the SC terminals, while a slug of drier low level air has caused erosion of the IFR/LIFR cigs at KILM and near KLBT. MVFR cigs are still noted near and to the NW of KLBT. Showers are currently moving ENE just NW of KFLO/KLBT. Model guidance is suggesting improvement to MVFR this morning and remaining MVFR into this afternoon, except at KFLO where cigs will remain IFR. This seems reasonable based on current cig trends thus confidence of improvement is moderate, but confidence of timing in TAFs is low. Overrunning moisture will produce periods of showers most likely KLBT/KFLO today, moving more towards the coast tonight. This should re-saturate the low level airmass. This evening and overnight there is high confidence of IFR/LIFR at KFLO/KLBT with IFR/LIFR developing at the coastal terminals mainly after midnight. Extended Outlook...Showers/MVFR likely with periods of IFR through Sat. Showers decrease with improvement to VFR Sun. VFR Mon. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 10 AM Thursday...Low pressure several hundred miles east of Cape Hatteras is moving out to sea and will lose its influence on our weather today. Easterly wind directions should dominate the area this afternoon with wind speeds remaining 10 knots or less. A slug of relatively dry air moving southward down the coastline this morning will tend to keep weather conditions dry, however some showers are possible by late afternoon, especially across the South Carolina coastal waters. Tonight air pressure will begin to drop across Georgia in association with another incoming upper level disturbance. This should tighten the local pressure gradient substantially and will lead to deteriorating marine conditions, particularly after midnight. By daybreak Friday northeast winds could be approaching 20 knots with seas building beyond 4 feet. Scattered showers are possible. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 315 AM Thursday...A baggy wave of low pressure will develop early Friday along a warm front across eastern Georgia and southernmost South Carolina. Stiff northeasterly winds Friday will be the result of the tightened pressure gradient just north of the front. At this time it appears conditions should remain just below Small Craft Advisory criteria, but it would only take another 5 knots or 1 foot in sea heights to change that. Winds should diminish Friday evening as the warm front moves across our area. The low should finally take shape as a closed feature on the weather map by Saturday morning across the northern Outer Banks, deepening as it moves northeastward into the open Atlantic Saturday night. The best chance for showers and t-storms will occur Friday Night as the wave of low pressure moves overhead along the warm front. LONG TERM /SUNDAY THROUGH MONDAY/... As of 315 AM Thursday...A north to northwest flow will be in place Sunday in between high pressure to the west and slowly departing low pressure to the northeast. Wind speeds will be 10-15 knots. Similar synoptic conditions Monday albeit with a weaker gradient. Significant seas will remain capped at 2-4, mostly 2-3 feet. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...MJC NEAR TERM...MJC SHORT TERM...TRA LONG TERM...SHK AVIATION...MRR MARINE...TRA/SHK
  [top] Area Forecast Discussion National Weather Service Newport/Morehead City NC 920 AM EDT THU MAY 19 2016 .SYNOPSIS... Low pressure off the coast will continue to move northeast away from the area today. High pressure will extend into the area from the north through Friday. Low pressure will develop to the southwest late Friday night then lift northeast across the region Saturday. The low will lift northeast of the area Saturday night and Sunday pushing a cold front offshore. Low pressure will develop well offshore early next week as high pressure builds south of the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 910 AM Thursday...Satellite and regional radars show band of shra to the west slowly spreading east. Models slowly push this activity toward eastern NC, however little if any expected to make it all the way to coast. Given strong sunshine currently occurring over region bumped up temps a couple degrees with 70 to 75 expected most spots. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... As of 4 AM Thursday...Will continue a small chance of rain over mainly southern sections tonight with weak mid-level disturbances and a fairly saturated low-level airmass in place per forecast soundings. Another cool night under mostly cloudy skies with low temperature 55 to 60 degrees area-wide. Again, any QPF tonight will be very light. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 320 am Thursday...Active and unsettled pattern will continue for the first several days of the period with below normal temps...then a gradual warming and drying trend mid to late next week. Friday through Saturday night: High pressure will shift eastward through the Mid-Atlantic states, moving offshore by early Saturday. Northerly flow will start to veer easterly Friday as the surface high shifts offshore. Will continue sc/chance pops Friday, highest across the southern zones as weak low forms along stalled frontal boundary to the south. The warm front will lift north through the region Friday night into Saturday...as areas of low pressure continue to develop along the boundary. Increased pops to likely Friday night with models showing good agreement in widespread showers and isolated thunderstorms...as deep moisture increases over the area coupled with increasing lift and forcing from approaching trough and warm front. Periods of moderate to heavy rainfall will be possible Friday night into the first part of Saturday. NAM soundings show pwat values approaching 2 inches Saturday morning. Will continue categorical pops for the first part of Sat with pops gradually tapering off late Sat as cold front pushes through the region Sat afternoon/evening. Will continue sc thunderstorm mention. Think widespread clouds and precip will limit the instability, though cannot rule out a strong thunderstorm developing. Precip will continue to taper off Sat night as cold front pushes further offshore and low lifts ne. Low level thickness values support below normal temps, with highs in the 70s and lows in the 60s. Could see temps a few degrees cooler Saturday with widespread clouds/precip. Sat night lows in the mid 50s to lower 60s. Sunday through Monday night: The surface low will continue to move off the Mid-Atlantic coast Sunday with the closed upper low becoming anchored across the Eastern CONUS through midweek. This will then provide continued cloud cover and slight chance showers Sunday and Monday. Highs in the low/mid 70s and lows in the mid 50s to low 60s. Tuesday through Wednesday: The upper low will lift ne into New England Tuesday into Tuesday night. While, high pressure quickly builds in, shifting offshore by Wednesday ushering in warm return flow and more seasonable temperatures. High temps Tuesday will be in the upper 70s and rebound into the low/mid 80s by Wednesday. Given moisture return and modest instability, an isolated seabreeze shower/tstm will be possible each afternoon && .AVIATION /13Z THURSDAY THROUGH MONDAY/... Short Term /through 12Z Friday/... As of 650 AM Thursday, as area of clearing developed along the Highway 17 corridor, patches of light fog has formed at several of the TAF sites. Latest satellite imagery and surface observations show that lower clouds are moving east and should arrive in our CWA by mid to late morning. Will forecast MVFR ceilings at all TAF sites and continuing into tonight as low-level moisture remains locked in across the region. Forecast confidence moderate at best. Long Term /Friday through Monday/... As of 330 am Thursday...Periods of sub-VFR conditions expected Friday into Sunday. Scattered showers expected Friday, becoming widespread Friday night into the first part of Saturday. The best chance of IFR will be Friday night into early Saturday. Drier air will gradually filter into the region Sat night into Sunday behind the cold front, with predominant VFR conditions returning Sunday night and Monday. && .MARINE... Short Term /through tonight/... As of 915 AM Thursday...No changes with NNE winds continuing as high pressure builds north of the area. Previous discussion...Seas have dropped below 6 feet at all locations and SCA was allowed to expire at 6 am. N/NE winds at 10-20 knots will prevail for the balance of the day with seas at 3-5 feet. As the surface low moves further offshore tonight, winds should be at or below 15 knots with seas generally 2-4 feet. Long Term /Friday through Monday/... As of 330 am Thursday...High pressure north of the area will shift off the coast Friday. East to northeast winds will increase to 10-20 knots Friday with stalled frontal boundary to the south allowing seas to build to 3-5 feet south of Oregon Inlet. A warm front will lift north through the waters Friday night and early Saturday, as areas of low pressure develop along the front, then the associated cold front will push through the waters Sat afternoon and evening. Southeast winds will increase to 15-25 knots Friday night, then become southerly early afternoon just ahead of the front. Will continue to show seas building to 4-7 feet. Small craft conditions likely to develop Friday night and continue into Sat night/Sun afternoon. Behind the front, winds shift northwesterly Saturday night with wind speeds 10-20 kts, helping to maintain seas 4 to 6 feet across the northern waters. Predominant northerly flow 10-15 knots will continue over the waters Sunday into Monday, as cold front pushes offshore, surface low lifts northeast and upper low strengthens over the Mid- Atlantic region. Elevated seas 4-6 feet north of Ocracoke will gradually subside to 3-5 feet late Sunday. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...CTC NEAR TERM...RF/CTC SHORT TERM...CTC LONG TERM...CQD/DAG AVIATION...CTC/CQD MARINE...RF/CTC/CQD
Area Forecast Discussion National Weather Service Wilmington NC 737 AM EDT THU MAY 19 2016 .SYNOPSIS... High pressure will build from the north today. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /THROUGH TONIGHT/... As of 635 am Thursday...Surface low pressure is now several hundred miles east of Cape Hatteras and moving farther out to sea. An in-situ wedge has developed with plenty of low stratus clouds covering NC and the eastern third of SC. An interesting mesoscale slug of dry air across far-eastern North Carolina has some implications on the forecast for later today. Across the western Carolinas a mid-level disturbance and low-level convergence along an inverted surface trough has developed a small but impressive area of showers and embedded thunderstorms. This activity will tend to drift eastward with time and I have increased forecast POPs along the I-95 corridor into the 60-90 percent range by noontime. Remember that slug of dry air dropping southward from far-eastern North Carolina? That should eat into the eastern edge of the dense clouds and precip today, limiting the chance of measurable precipitation in the Cape Fear region and as far south as Myrtle Beach. Dense clouds could hang in all day near and west of I-95, and with the higher chance of rain temperatures may struggle into the upper 60s today. Near the coast where there should be some sun highs should reach the mid to upper 70s: warmer but still below normal for the date. Late tonight a synoptic warm front will begin to lift northward across Georgia and southernmost South Carolina. Although the best synoptic lift will wait until later Friday to arrive, scattered showers appear possible given the juxtaposition of low-level ascent and moisture near and north of the front. Forecast POPs are 40-50 percent tonight, with lows expected to range from 59-64. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 315 am Thursday...The main feature of note in the Friday- Saturday portion of the forecast is an impressive upper level disturbance expected to roll eastward from the lower Mississippi Valley across the Carolinas Friday night, then offshore Saturday afternoon. A surface wave of low pressure will develop along a warm front across Georgia and southern Carolina early Friday, bowing northward into southeastern North Carolina late Friday night into early Saturday. As the low exits the North Carolina coast Saturday the front will be pushed southward and offshore. The best synoptic lift should occur late Friday night into Saturday morning when my forecast POPs are in the 70-80 percent range with QPF 0.5 to 1.0 inches. Given the time of day the risk for severe weather appears minimal, however thunderstorms certainly remain in the forecast given sufficiently steep mid-level lapse rates. A model blend, heavy on the GFS, has been used for temperatures through the period. There is larger than normal uncertainly with regard to high temperatures on Saturday. Recent model trends have shown a much quicker clearing trend developing with this morning`s 00z models now suggesting there could be a good deal of sunshine Saturday afternoon, especially across South Carolina. While a couple of days ago we were anticipating plenty of clouds to hang in with northerly surface winds, this new idea could lead to temperatures soaring much higher than originally anticipated. We`ll see what the next round of models do with this Saturday clearing before making large adjustments to the forecast. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 315 am Thursday...Highly amplified pattern will relax somewhat by the latter part of next week. Initially a deep mid level trough will linger over the Delmarva region before getting kicked out Monday. Overall trends for pops have decreased beyond Sunday when a few showers may develop with the feature. The broad southwest flow that develops may bring in some moisture late in the period as surface high pressure moves offshore. A little too early to add any mention of pops as the system is very diffuse at this point. Temperature guidance points to a steady warming trend through the period with climatological normals by the end of the period. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... As of 12Z...Weak surface high pressure is located over the terminals this morning. This is resulting in light NE winds at the coast and light E winds inland. LIFR/IFR conditions are affecting the SC terminals, while a slug of drier low level air has caused erosion of the IFR/LIFR cigs at KILM and near KLBT. MVFR cigs are still noted near and to the NW of KLBT. Showers are currently moving ENE just NW of KFLO/KLBT. Model guidance is suggesting improvement to MVFR this morning and remaining MVFR into this afternoon, except at KFLO where cigs will remain IFR. This seems reasonable based on current cig trends thus confidence of improvement is moderate, but confidence of timing in TAFs is low. Overrunning moisture will produce periods of showers most likely KLBT/KFLO today, moving more towards the coast tonight. This should re-saturate the low level airmass. This evening and overnight there is high confidence of IFR/LIFR at KFLO/KLBT with IFR/LIFR developing at the coastal terminals mainly after midnight. Extended Outlook...Showers/MVFR likely with periods of IFR through Sat. Showers decrease with improvement to VFR Sun. VFR Mon. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 635 AM Thursday...Low pressure now several hundred miles east of Cape Hatteras is moving out to sea and will lose its influence on our weather today. Stiff northeasterly winds of Wednesday evening have faded away and winds are currently 10 knots or less at all observation platforms. Easterly wind directions should dominate the area this afternoon with wind speeds remaining 10 knots or less. A slug of relatively dry air moving southward down the coastline this morning will tend to keep weather conditions dry, however some showers are possible by late afternoon, especially across the South Carolina coastal waters. Tonight air pressure will begin to drop across Georgia in association with another incoming upper level disturbance. This should tighten the local pressure gradient substantially and will lead to deteriorating marine conditions, particularly after midnight. By daybreak Friday northeast winds could be approaching 20 knots with seas building beyond 4 feet. Scattered showers are possible. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 315 AM Thursday...A baggy wave of low pressure will develop early Friday along a warm front across eastern Georgia and southernmost South Carolina. Stiff northeasterly winds Friday will be the result of the tightened pressure gradient just north of the front. At this time it appears conditions should remain just below Small Craft Advisory criteria, but it would only take another 5 knots or 1 foot in sea heights to change that. Winds should diminish Friday evening as the warm front moves across our area. The low should finally take shape as a closed feature on the weather map by Saturday morning across the northern Outer Banks, deepening as it moves northeastward into the open Atlantic Saturday night. The best chance for showers and t-storms will occur Friday Night as the wave of low pressure moves overhead along the warm front. LONG TERM /SUNDAY THROUGH MONDAY/... As of 315 AM Thursday...A north to northwest flow will be in place Sunday in between high pressure to the west and slowly departing low pressure to the northeast. Wind speeds will be 10-15 knots. Similar synoptic conditions Monday albeit with a weaker gradient. Significant seas will remain capped at 2-4, mostly 2-3 feet. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...SHK NEAR TERM...TRA SHORT TERM...TRA LONG TERM...SHK AVIATION...MRR
Area Forecast Discussion National Weather Service Newport/Morehead City NC 649 AM EDT THU MAY 19 2016 .SYNOPSIS... Low pressure off the coast will continue to move northeast away from the area today. High pressure will extend into the area from the north through Friday. Low pressure will develop to the southwest late Friday night then lift northeast across the region Saturday. The low will lift northeast of the area Saturday night and Sunday pushing a cold front offshore. Low pressure will develop well offshore early next week as high pressure builds south of the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 645 AM Thursday, Skies have cleared along and east of the Highway 17 corridor with some patches of fog reported. Mid-level energy and increased moisture/isentropic lift and light rain to our west will move into our CWA by mid to late morning and have a small chance of showers mainly west of Highway 17 this afternoon. Have the highest PoPs over the far southwestern portion of the CWA, tapering to the north. Any QPF values will be very low, mainly a few hundreths of an inch. Kept the coastal sections generally dry today. Temperatures are likewise tricky today as any sunshine could push readings well into the 70s, but trended toward a cloudier forecast with highs upper 60s coast to generally lower 70s elsewhere. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... As of 4 AM Thursday...Will continue a small chance of rain over mainly southern sections tonight with weak mid-level disturbances and a fairly saturated low-level airmass in place per forecast soundings. Another cool night under mostly cloudy skies with low temperature 55 to 60 degrees area-wide. Again, any QPF tonight will be very light. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 320 am Thursday...Active and unsettled pattern will continue for the first several days of the period with below normal temps...then a gradual warming and drying trend mid to late next week. Friday through Saturday night: High pressure will shift eastward through the Mid-Atlantic states, moving offshore by early Saturday. Northerly flow will start to veer easterly Friday as the surface high shifts offshore. Will continue sc/chance pops Friday, highest across the southern zones as weak low forms along stalled frontal boundary to the south. The warm front will lift north through the region Friday night into Saturday...as areas of low pressure continue to develop along the boundary. Increased pops to likely Friday night with models showing good agreement in widespread showers and isolated thunderstorms...as deep moisture increases over the area coupled with increasing lift and forcing from approaching trough and warm front. Periods of moderate to heavy rainfall will be possible Friday night into the first part of Saturday. NAM soundings show pwat values approaching 2 inches Saturday morning. Will continue categorical pops for the first part of Sat with pops gradually tapering off late Sat as cold front pushes through the region Sat afternoon/evening. Will continue sc thunderstorm mention. Think widespread clouds and precip will limit the instability, though cannot rule out a strong thunderstorm developing. Precip will continue to taper off Sat night as cold front pushes further offshore and low lifts ne. Low level thickness values support below normal temps, with highs in the 70s and lows in the 60s. Could see temps a few degrees cooler Saturday with widespread clouds/precip. Sat night lows in the mid 50s to lower 60s. Sunday through Monday night: The surface low will continue to move off the Mid-Atlantic coast Sunday with the closed upper low becoming anchored across the Eastern CONUS through midweek. This will then provide continued cloud cover and slight chance showers Sunday and Monday. Highs in the low/mid 70s and lows in the mid 50s to low 60s. Tuesday through Wednesday: The upper low will lift ne into New England Tuesday into Tuesday night. While, high pressure quickly builds in, shifting offshore by Wednesday ushering in warm return flow and more seasonable temperatures. High temps Tuesday will be in the upper 70s and rebound into the low/mid 80s by Wednesday. Given moisture return and modest instability, an isolated seabreeze shower/tstm will be possible each afternoon && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Short Term /through 12Z Friday/... As of 650 AM Thursday, as area of clearing developed along the Highway 17 corridor, patches of light fog has formed at several of the TAF sites. Latest satellite imagery and surface observations show that lower clouds are moving east and should arrive in our CWA by mid to late morning. Will forecast MVFR ceilings at all TAF sites and continuing into tonight as low-level moisture remains locked in across the region. Forecast confidence moderate at best. Long Term /Friday through Monday/... As of 330 am Thursday...Periods of sub-VFR conditions expected Friday into Sunday. Scattered showers expected Friday, becoming widespread Friday night into the first part of Saturday. The best chance of IFR will be Friday night into early Saturday. Drier air will gradually filter into the region Sat night into Sunday behind the cold front, with predominant VFR conditions returning Sunday night and Monday. && .MARINE... Short Term /through tonight/... As of 650 AM Thursday, seas have dropped below 6 feet at all locations and SCA was allowed to expire at 6 am. N/NE winds at 10-20 knots will prevail for the balance of the day with seas at 3-5 feet. As the surface low moves further offshore tonight, winds should be at or below 15 knots with seas generally 2-4 feet. Long Term /Friday through Monday/... As of 330 am Thursday...High pressure north of the area will shift off the coast Friday. East to northeast winds will increase to 10-20 knots Friday with stalled frontal boundary to the south allowing seas to build to 3-5 feet south of Oregon Inlet. A warm front will lift north through the waters Friday night and early Saturday, as areas of low pressure develop along the front, then the associated cold front will push through the waters Sat afternoon and evening. Southeast winds will increase to 15-25 knots Friday night, then become southerly early afternoon just ahead of the front. Will continue to show seas building to 4-7 feet. Small craft conditions likely to develop Friday night and continue into Sat night/Sun afternoon. Behind the front, winds shift northwesterly Saturday night with wind speeds 10-20 kts, helping to maintain seas 4 to 6 feet across the northern waters. Predominant northerly flow 10-15 knots will continue over the waters Sunday into Monday, as cold front pushes offshore, surface low lifts northeast and upper low strengthens over the Mid- Atlantic region. Elevated seas 4-6 feet north of Ocracoke will gradually subside to 3-5 feet late Sunday. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...CQD/DAG AVIATION...CTC/CQD MARINE...CTC/CQD
Area Forecast Discussion National Weather Service Raleigh NC 305 AM EDT Thu May 19 2016 .SYNOPSIS...An upper level disturbance will push across the region today. A weak and cool surface high pressure will continue to extend into central North Carolina through Friday. A much stronger storm system is expected to move into the region late Friday into early Saturday. && .NEAR TERM /through tonight/... As of 122 AM Thursday... The main issues to deal with today will be the rain chances associated with the upper disturbance, and the expected persistent chilly NE low level supply of cool stable air and overcast associated with the hybrid CAD, resulting in temperatures again 20- 25 degrees below normal for highs. The predominate NE flow continued along the Appalachians and east coast states this morning, courtesy of the low pressure exiting into the western Atlantic and the surface high pressure located over the lower Great Lakes states. This flow is one that continues to advect cool and some marginally drier air into the state from central VA. The NE-E flow extended all the way into central SC and northeast GA where a weak low pressure was noted. Some drier air was trying to work down the coast from the north with some partial clearing of the low clouds noted east of I-95. There was a weakness in the pressure pattern noted over the Appalachians associated with the current weak hybrid CAD high pressure over NC/VA and the stronger high located over the lower Great Lakes states. Radar indicated scattered showers and thunderstorms developing over upstate SC spreading NE into western NC to near Hickory and Statesville. This is area was associated with the approaching upper level disturbance and the mass convergence near the surface wave and front stalled over upstate SC. For the chances of rain today, the latest Hi-Res convection allowing models support the current radar trends in bringing an area of showers and general rain (north in the cool stable air) across the Piedmont this morning. This occurs as the low level flow remains NE bringing a continuous supply of cool stable air into the Piedmont Damming region. This scenario above is favored by the conventional GFS/NAM as well. MOS guidance finally caught up with the much cooler stable temperatures yesterday associated with the NE flow and damming; therefore, we will not have to adjust guidance down as much today as we did yesterday. Bottom line today, expect a good chance of showers in the SE Coastal Plain with occasional rain over the Piedmont. Most of the rain should be light with QPF of around 0.25 expected in the Piedmont, lesser amounts over the Coastal Plain. Temperatures should only go up 3-5 degrees or so as the low overcast develops/persists through the day. Highs only in the 50s NW and N Piedmont ranging into the upper 60s SE. Significant rain chances lower tonight in the rear of the upper disturbance departing to the NE. However, the low overcast conditions should continue tonight enhanced by the low level NNE flow. In fact, the main chilly surface high pressure is forecast to move east to PA later tonight. The high is of sufficient strength and in a proper position to deliver additional cool stable air into the region to allow for the persistence of the CAD, then enhancement of the CAD Friday into Friday night as the next storm approaches from the SW (see discussion below). Lows tonight 50s except lower 60s SE. && .SHORT TERM /Friday through Saturday/... As of 258 aM Thursday... ...Hybrid CAD and Miller B storm system to affect the region into early Saturday... Issues ahead for Friday through Saturday will be mainly with the rainfall forecasts and the continued very cool temperatures for daily highs through at least Saturday. Any severe threat associated with the approaching storm system late Friday and Friday night have essentially been erased by the agreement of the models with hybrid CAD over our region and by the forecast of the storm track to be up along or east of I-95 late Friday night and early Saturday. This storm track is more of a Miller B with one low lifting NE through the TN and OH valley as another develops along the SC/NC coastal area late Friday night, then tracks up the coast Saturday. This pattern has a cool stable and almost "wintry" look to it. To begin Friday, a very cool surface high pressure is forecast to be centered over PA. The strength is expected to be around 1025 MB. The location and strength are both sufficient to deliver additional cool stable air into central NC from the north Friday. This occurs as the initial low pressure is forecast to track NE into the TN valley region by late Friday. All of our region is expected to be dominated by the cool stable low level high to the north. As such, temperatures Friday will be hard pressed to get out of the 60s anywhere in the region. Some upper 50s may again linger around the Triad to Roxboro in the continued hybrid CAD resume. The CAD will be strengthen as the day goes on as a cool stable NE flow pumps into the damming region of the Piedmont. Models suggest that some areas of light rain may develop/overspread portions of the Piedmont during the afternoon before widespread rain arrives Friday night. Even though the parent surface high will move offshore of New England Friday, the cool stable dome will have already been enhanced and firmly established. The coastal front is forecast to be pinned at the immediate coast. As one storm lifts NE toward the central Appalachians, another one will develop and take over near the boundary along the SC coast Friday night. This low will then lift NE along the coast early Saturday. There will be very little chance in this scenario of the coastal front being pulled inland, thus eliminating the severe risk over our region. However, a few elevated thunderstorms are expected to be embedded in the large rain area that overspreads the region Friday night, then ends from the southwest Saturday morning. The storm will then lift away from the region Saturday afternoon with dramatically lowering POP. However... the northerly flow behind the system along with lingering moisture in the low levels should keep any partial clearing confined to the SW Piedmont Saturday afternoon. Highs will be held down again by the residual CAD and then the persistent northerly flow as the storm pulls away. Expect readings to be warmest where any breaks occur in the SW Piedmont (possibly near 70). Most areas will stay in the lower to mid 60s (which is a good 20 degrees below normal). QPF will continue to be a tough call given the complexity of the evolving storm and the hybrid CAD over inland areas. Not to mention the deep south/Gulf coast convection potential. Even though models continue to be generous with 1 to locally 1.5 inches, this may be overdone in some areas. Flash flooding is not anticipated with the lack of strong convection and with the FFG values running rather high in the 3+ inch range in 6 hours. This is not expected to be threatened. But 1 to 1.5 inches in 6 hours may result in some minor flooding in urban and flood prone areas. && .LONG TERM /Saturday night through Wednesday/... As of 3 AM Thursday... Additional energy is expected to dive southward out of Canada helping to close off into a mid/upper level low along the mid atlantic coast late weekend into early next week, which will result in continue chances for showers and possibly some storms depending on the placement of the mid/upper low for Sunday and Monday (chance of convection everywhere for Sunday and limited to just eastern portions of the area my Monday). However, the best chance for precip will be during the afternoon into the evening/more diurnally driven convection. Highs Sunday and Monday are expected to remaining below normal in the 70s. Highs Tuesday and Wednesday will return to more seasonable values as the mid/upper low is expected to lift off to the northeast and surface high pressure is expected to shift offshore finally. Lows temps are expected to be near to slightly below normal for the medium range. && .AVIATION /06Z Thursday through Monday/... As of 125 AM Thursday... Low ceilings and occasionally low visibilities as well will persist today and tonight. Occasional rain and drizzle can be expected in the region along with persistent MVFR becoming IFR CIGS at or below 1K feet today. Abundant moisture will continue the low ceilings through tonight and into Friday. However, surface visibilities should improve somewhat Friday before falling again to IFR with rain and fog late Friday into Saturday morning. This occurs as a low level NE flow strengthens out ahead of an approaching storm system from the SW Friday night. This storm is expected to lift N of the region Saturday afternoon. The outlook for Saturday late through Sunday is for improving aviation conditions as the widespread rain/fog move north of the region between 12z-18z Saturday. VFR conditions are expected Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...Badgett/BSD LONG TERM...BSD AVIATION...Badgett
Area Forecast Discussion National Weather Service Raleigh NC 258 AM EDT Thu May 19 2016 .SYNOPSIS...An upper level disturbance will push across the region today. A weak and cool surface high pressure will continue to extend into central North Carolina through Friday. A much stronger storm system is expected to move into the region late Friday into early Saturday. && .NEAR TERM /through tonight/... As of 122 AM Thursday... The main issues to deal with today will be the rain chances associated with the upper disturbance, and the expected persistent chilly NE low level supply of cool stable air and overcast associated with the hybrid CAD, resulting in temperatures again 20- 25 degrees below normal for highs. The predominate NE flow continued along the Appalachians and east coast states this morning, courtesy of the low pressure exiting into the western Atlantic and the surface high pressure located over the lower Great Lakes states. This flow is one that continues to advect cool and some marginally drier air into the state from central VA. The NE-E flow extended all the way into central SC and northeast GA where a weak low pressure was noted. Some drier air was trying to work down the coast from the north with some partial clearing of the low clouds noted east of I-95. There was a weakness in the pressure pattern noted over the Appalachians associated with the current weak hybrid CAD high pressure over NC/VA and the stronger high located over the lower Great Lakes states. Radar indicated scattered showers and thunderstorms developing over upstate SC spreading NE into western NC to near Hickory and Statesville. This is area was associated with the approaching upper level disturbance and the mass convergence near the surface wave and front stalled over upstate SC. For the chances of rain today, the latest Hi-Res convection allowing models support the current radar trends in bringing an area of showers and general rain (north in the cool stable air) across the Piedmont this morning. This occurs as the low level flow remains NE bringing a continuous supply of cool stable air into the Piedmont Damming region. This scenario above is favored by the conventional GFS/NAM as well. MOS guidance finally caught up with the much cooler stable temperatures yesterday associated with the NE flow and damming; therefore, we will not have to adjust guidance down as much today as we did yesterday. Bottom line today, expect a good chance of showers in the SE Coastal Plain with occasional rain over the Piedmont. Most of the rain should be light with QPF of around 0.25 expected in the Piedmont, lesser amounts over the Coastal Plain. Temperatures should only go up 3-5 degrees or so as the low overcast develops/persists through the day. Highs only in the 50s NW and N Piedmont ranging into the upper 60s SE. Significant rain chances lower tonight in the rear of the upper disturbance departing to the NE. However, the low overcast conditions should continue tonight enhanced by the low level NNE flow. In fact, the main chilly surface high pressure is forecast to move east to PA later tonight. The high is of sufficient strength and in a proper position to deliver additional cool stable air into the region to allow for the persistence of the CAD, then enhancement of the CAD Friday into Friday night as the next storm approaches from the SW (see discussion below). Lows tonight 50s except lower 60s SE. && .SHORT TERM /Friday through Saturday/... As of 258 aM Thursday... ...Hybrid CAD and Miller B storm system to affect the region into early Saturday... Issues ahead for Friday through Saturday will be mainly with the rainfall forecasts and the continued very cool temperatures for daily highs through at least Saturday. Any severe threat associated with the approaching storm system late Friday and Friday night have essentially been erased by the agreement of the models with hybrid CAD over our region and by the forecast of the storm track to be up along or east of I-95 late Friday night and early Saturday. This storm track is more of a Miller B with one low lifting NE through the TN and OH valley as another develops along the SC/NC coastal area late Friday night, then tracks up the coast Saturday. This pattern has a cool stable and almost "wintry" look to it. To begin Friday, a very cool surface high pressure is forecast to be centered over PA. The strength is expected to be around 1025 MB. The location and strength are both sufficient to deliver additional cool stable air into central NC from the north Friday. This occurs as the initial low pressure is forecast to track NE into the TN valley region by late Friday. All of our region is expected to be dominated by the cool stable low level high to the north. As such, temperatures Friday will be hard pressed to get out of the 60s anywhere in the region. Some upper 50s may again linger around the Triad to Roxboro in the continued hybrid CAD resume. The CAD will be strengthen as the day goes on as a cool stable NE flow pumps into the damming region of the Piedmont. Models suggest that some areas of light rain may develop/overspread portions of the Piedmont during the afternoon before widespread rain arrives Friday night. Even though the parent surface high will move offshore of New England Friday, the cool stable dome will have already been enhanced and firmly established. The coastal front is forecast to be pinned at the immediate coast. As one storm lifts NE toward the central Appalachians, another one will develop and take over near the boundary along the SC coast Friday night. This low will then lift NE along the coast early Saturday. There will be very little chance in this scenario of the coastal front being pulled inland, thus eliminating the severe risk over our region. However, a few elevated thunderstorms are expected to be embedded in the large rain area that overspreads the region Friday night, then ends from the southwest Saturday morning. The storm will then lift away from the region Saturday afternoon with dramatically lowering POP. However... the northerly flow behind the system along with lingering moisture in the low levels should keep any partial clearing confined to the SW Piedmont Saturday afternoon. Highs will be held down again by the residual CAD and then the persistent northerly flow as the storm pulls away. Expect readings to be warmest where any breaks occur in the SW Piedmont (possibly near 70). Most areas will stay in the lower to mid 60s (which is a good 20 degrees below normal). QPF will continue to be a tough call given the complexity of the evolving storm and the hybrid CAD over inland areas. Not to mention the deep south/Gulf coast convection potential. Even though models continue to be generous with 1 to locally 1.5 inches, this may be overdone in some areas. Flash flooding is not anticipated with the lack of strong convection and with the FFG values running rather high in the 3+ inch range in 6 hours. This is not expected to be threatened. But 1 to 1.5 inches in 6 hours may result in some minor flooding in urban and flood prone areas. && .LONG TERM /Saturday night through Wednesday/... As of 230 PM Wednesday... Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /06Z Thursday through Monday/... As of 125 AM Thursday... Low ceilings and occasionally low visibilities as well will persist today and tonight. Occasional rain and drizzle can be expected in the region along with persistent MVFR becoming IFR CIGS at or below 1K feet today. Abundant moisture will continue the low ceilings through tonight and into Friday. However, surface visibilities should improve somewhat Friday before falling again to IFR with rain and fog late Friday into Saturday morning. This occurs as a low level NE flow strengthens out ahead of an approaching storm system from the SW Friday night. This storm is expected to lift N of the region Saturday afternoon. The outlook for Saturday late through Sunday is for improving aviation conditions as the widespread rain/fog move north of the region between 12z-18z Saturday. VFR conditions are expected Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...Badgett/BSD LONG TERM...KRD AVIATION...Badgett
Area Forecast Discussion National Weather Service Raleigh NC 122 AM EDT Thu May 19 2016 .SYNOPSIS...An upper level disturbance will push across the region today. A weak and cool surface high pressure will continue to extend into central North Carolina through Friday. A much stronger storm system is expected to move into the region late Friday into early Saturday. && .NEAR TERM /through tonight/... As of 122 AM Thursday... The main issues to deal with today will be the rain chances associated with the upper disturbance, and the expected persistent chilly NE low level supply of cool stable air and overcast associated with the hybrid CAD, resulting in temperatures again 20- 25 degrees below normal for highs. The predominate NE flow continued along the Appalachians and east coast states this morning, courtesy of the low pressure exiting into the western Atlantic and the surface high pressure located over the lower Great Lakes states. This flow is one that continues to advect cool and some marginally drier air into the state from central VA. The NE-E flow extended all the way into central SC and northeast GA where a weak low pressure was noted. Some drier air was trying to work down the coast from the north with some partial clearing of the low clouds noted east of I-95. There was a weakness in the pressure pattern noted over the Appalachians associated with the current weak hybrid CAD high pressure over NC/VA and the stronger high located over the lower Great Lakes states. Radar indicated scattered showers and thunderstorms developing over upstate SC spreading NE into western NC to near Hickory and Statesville. This is area was associated with the approaching upper level disturbance and the mass convergence near the surface wave and front stalled over upstate SC. For the chances of rain today, the latest Hi-Res convection allowing models support the current radar trends in bringing an area of showers and general rain (north in the cool stable air) across the Piedmont this morning. This occurs as the low level flow remains NE bringing a continuous supply of cool stable air into the Piedmont Damming region. This scenario above is favored by the conventional GFS/NAM as well. MOS guidance finally caught up with the much cooler stable temperatures yesterday associated with the NE flow and damming; therefore, we will not have to adjust guidance down as much today as we did yesterday. Bottom line today, expect a good chance of showers in the SE Coastal Plain with occasional rain over the Piedmont. Most of the rain should be light with QPF of around 0.25 expected in the Piedmont, lesser amounts over the Coastal Plain. Temperatures should only go up 3-5 degrees or so as the low overcast develops/persists through the day. Highs only in the 50s NW and N Piedmont ranging into the upper 60s SE. Significant rain chances lower tonight in the rear of the upper disturbance departing to the NE. However, the low overcast conditions should continue tonight enhanced by the low level NNE flow. In fact, the main chilly surface high pressure is forecast to move east to PA later tonight. The high is of sufficient strength and in a proper position to deliver additional cool stable air into the region to allow for the persistence of the CAD, then enhancement of the CAD Friday into Friday night as the next storm approaches from the SW (see discussion below). Lows tonight 50s except lower 60s SE. && .SHORT TERM /Thursday and Thursday night/... As of 330 PM Wednesday... WRF models along with a few near term models have trended wetter than previous runs for Thursday...apparently keying on the weak shear axis and inverted sfc trough. The WRF models are likely overdone considering they are overplaying the rain showers this afternoon in vicinity of the higher terrain in western NC. While the GFS and ECMWF both depict the inverted sfc trough washing out...being replaced by a narrow ridge of high pressure...model guidance still depicting measurable rain over most of central NC on Thursday. Models may be keying on confluence along a west-to-east 850mb boundary in vicinity of highway 64. Cross sections, however, reveal that the lift, weak as it is, is confined to the lowest 8k ft or so of the atmosphere. Thus, having a tough time buying into the high end likely/low end categorical pops across the area for Thursday. Appears highest threat for measurable rain will be Thursday morning...and mainly confined to the far SW. After 16Z, rain chances should be no more than a chance and highest over the south. Extensive cloud cover and chances for precip will prevent temps from warming much above overnight low temps. High temps should vary from the low-mid 60s north to the lower 70s se. If rain is more extensive than forecast, high temp may end up being 3-5 degrees cooler. Weak isentropic upglide late Thursday night will yield spots of light rain...especially after 04Z and mainly over the sw third of the forecast area. Min temps generally in the mid-upper 50s. && .LONG TERM /Friday through Wednesday/... As of 230 PM Wednesday... Friday through Saturday: High pressure will be extending down the east coast to begin the long term period, with a cold air damming regime setting up over the region. At the same time, a short wave will be moving towards the area from the west and this will set the stage for a rather wet period. A couple of waves of low pressure are progged to track near/along the CAD boundary that will set up across the area. Precip chances will increase from west to east throughout the day on Friday, with the best time frame being Friday night/early Saturday morning. Given the high shear/low cape environment that is expected, the severe weather threat is expected to be rather low, especially given the poor diurnal timing. The bigger threat is going to be the heavy rain potential, where average rainfall amounts are expected to range from around an inch across the southeast to possibly around 2 inches or more across the Northwest Piedmont, which could cause some minor flooding in urban areas or poor drainage locations. The majority of the precip should shift off to the northeast throughout the afternoon on Saturday, although persistent cyclonic flow aloft will linger across the area and will result in mostly cloudy skies and possibly a lingering showers into Saturday night. Given the CAD regime, high temps should range from low/mid 70s across the southeast to the low/mid 60s across the northwest. Sunday through Wednesday: Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /06Z Thursday through Monday/... As of 125 AM Thursday... Low ceilings and occasionally low visibilities as well will persist today and tonight. Occasional rain and drizzle can be expected in the region along with persistent MVFR becoming IFR CIGS at or below 1K feet today. Abundant moisture will continue the low ceilings through tonight and into Friday. However, surface visibilities should improve somewhat Friday before falling again to IFR with rain and fog late Friday into Saturday morning. This occurs as a low level NE flow strengthens out ahead of an approaching storm system from the SW Friday night. This storm is expected to lift N of the region Saturday afternoon. The outlook for Saturday late through Sunday is for improving aviation conditions as the widespread rain/fog move north of the region between 12z-18z Saturday. VFR conditions are expected Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...WSS LONG TERM...KRD AVIATION...Badgett
Area Forecast Discussion National Weather Service Wilmington NC 933 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build from the north overnight into Thursday. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 933 PM Wednesday...No significant changes required with the middle evening updates as mostly cloudy skies prevail with local temperatures overnight very close to climatology for this time of May. No drivers for significant PCPN tonight aside from MCV perturbation showers west of I-95 after 2 AM. Low-level saturation late tonight may materialize a patch or 2 of drizzle, but for most locations, measurable rainfall is not likely. With low cloud ceilings and nearly saturated low level air, temperature drops will be slow to evolve, settling in the upper 50s to lower 60s daybreak Thursday. A pocket of mist or fog cannot be ruled out overnight as well given the very damp regime in place near the surface. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... As of 00Z...MVFR with brief improvement to VFR possible this evening before widespread MVFR/IFR returns with areas of fog possible overnight. Improvement to VFR on Thursday is expected with increasing chances for showers throughout the day. Though latest radar imagery remains fairly quiet this evening, satellite imagery continues to show broken to overcast coverage of low clouds allowing for widespread MVFR to prevail at the terminals. Trends do indicate the potential for brief improvement to VFR over the next few hours, before cloud coverage increases again overnight. This along with developing areas of fog will create MVFR/IFR through the early morning hours. Light and variable winds are expected. After daybreak, expect conditions to improve to VFR with increasing chances for showers into the afternoon hours. Northeasterly winds around 5 kts in the morning will become east-northeasterly in the afternoon around around 10 kts. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 933 PM Wednesday...`Exercise Caution" headline is needed for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly mellower wind-speeds over the SC waters precludes this headline. Caution headline valid until midnight tonight as wind trends ease this evening, as a low offshore of Cape Lookout moves NE away from the coast...thus a very brief cautionary period. Virtually no wave energy with wave periods greater than 7 seconds exists right now and all energy is tied to nearby winds...thus slightly steep and bumpy this evening for only 3-5 ft seas. Dominant wave periods will hold between 6-7 seconds overnight with little or no shower activity. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MJC SHORT TERM...DCH LONG TERM...III AVIATION...SGL
Area Forecast Discussion National Weather Service Newport/Morehead City NC 837 PM EDT WED MAY 18 2016 .SYNOPSIS... Low pressure off the coast will continue to move northeast away from the area tonight. High pressure will extend into the area from the north Thursday and Friday. Low pressure will develop to the southwest late Friday night then lift northeast across the region Saturday. The low will lift northeast of the area Saturday night and Sunday pushing a cold front offshore. Low pressure will develop well offshore early next week as high pressure builds south of the region. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 730 PM Wednesday...Updated to indicate some clearing over northern sections this evening per latest obs/satellite trends. Still expect some lower cloudiness to develop...thus kept mostly cloudy/cloudy forecast for overnight. Minor adjustments for latest hourly temp/dew point trends. /Previous discussion/ As of 230 PM Wednesday...Rain has rapidly diminished across the region and will lower pops to slight chc thru early evening with patchy light rain or drizzle...mainly near coast. Any lingering precip should end by mid evening as drier mid level air spreads in. Low levels will remain nearly saturated and expect good deal of clouds to persist thru the night. Lows will be mainly in the mid to upper 50s...poss holding around 60 central/southern beaches. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... As of 230 PM Wednesday...High pressure will build N of the area with mainly dry weather expected. Bulk of models do show some increase in moisture and light qpf SW tier late ahead of weak short wave so added slight pop this area. Plenty of clouds will continue over the region and with NNE surface flow temps will remain cool with highs low/mid 70s with some 60s Outer Banks. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As of 3 pm Wednesday...A very active weather pattern with below normal temps through a portion of the period. Thursday Night through Friday Night: High pressure will migrate eastward through the Mid-Atlantic states during the period, eventually moving offshore by early Saturday. North flow will start to veer easterly Friday as the surface high shifts offshore. Southeast flow increases Friday night as the next storm system approaches from the southwest. Introduced slight chance pops Thursday night into Friday for the southerly third of the CWA as a weak boundary remains south of the area with moisture lingering. PWATS increase rapidly Friday afternoon/evening as southwesterly flow in the mid levels brings in greater moisture across the area. Precip chances increase from slight chance late Friday to likelies late Friday night, partly due to a warm front lifting north through the region. Temps Friday will range low/mid 70s due to precip/clouds. Thursday night lows will range in the mid 50s to near 60 along the OBX, and mid/upper 60s areawide on Friday night. Saturday through Monday: A developing surface low will shift northeast through Eastern NC on Saturday as an upper trough digs southeast from the Great Lakes into the Mid-Atlantic region. This will result in a surface low developing/moving north of the area Saturday with a cold front crossing Saturday afternoon/evening. Given we will be under the warm sector ahead of the front with ample lift, moisture and sufficient instability/shear, the convective potential looks probable, especially in the afternoon. The timing of this front and the subsequent cloud cover will be a big factor in the severity/coverage of any storms that develop. It is a bit far out to iron out details at this point, but looks like the front crossing around late afternoon will limit convection in the evening. The surface low will move off the Mid- Atlantic coast Sunday with the closed upper low becoming anchored across the Eastern CONUS through midweek. This will then provide continued cloud cover and slight chance showers through the remainder of the period. Temps will remain in the low/mid 70s during this period, with the cooler day being Sunday after the front crosses and a surge of cooler air moves into the region. Tuesday through Wednesday: The closed upper low will finally lift northeast into New England with zonal flow developing by Wednesday. Meanwhile, high pressure quickly builds in, shifting offshore by Wednesday ushering in warm return flow and more seasonable temperatures. High temps Tuesday will be in the upper 70s and rebound into the low/mid 80s by Wednesday. Given moisture return and modest instability, introduced slight chance showers and thunderstorms for Wednesday afternoon for inland sections. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... Short Term /Through 00Z Friday/... As of 730 PM Wednesday...Problematic forecast for this evening as guidance is not in good agreement with latest obs trends. Most of guidance indicatest current mainly MVFR cigs lowering to IFR by late evening with IFR/LIFR then persisting into Thursday morning. However obs and satellite indicate clearing moving into NW sections as slightly drier air mass is advecting in as low pressure moves offshore. Have gone with obs trend next few hours...but with diminishing winds and moist low levels...still expect some IFR stratus to develop 03Z-06z and persist into morning. Cigs will improve to VFR by 15Z...but some increased lift may result in MVFR cigs again after 21Z. Forecast confidence moderate at best. Long Term /Thursday Night through Monday/... As of 310 pm Wednesday...High pressure to the north will persist through Friday, then eventually shifts offshore Friday Night. Expect VFR conditions through Friday, with some mid level clouds returning Thursday night through Friday especially for OAJ/EWN. With return flow quickly developing Friday afternoon and the increase in precipitation, expect lowering ceilings with sub-VFR conditions likely. Ample moisture will be present Friday night through much of Saturday ahead of a front that is progged to cross later Saturday. Lingering sub-VFR conditions can be expected early Sunday. Drier air will work its way into the region through the remainder of Sunday and into Monday. However, do expect lingering mid/upper level clouds Sunday under north flow. Predominant VFR expected Monday. && .MARINE... Short Term /Tonight and Thursday/... As of 730 PM Wednesday...No changes with update. /Previous discussion/ As of 230 PM Wednesday...NNE winds remain quite gusty along the coast to N and W of low pressure located SE of Cape Lookout. Winds should remain up along the coast into the evening before diminishing overnight as low departs. Seas of 5 to 8 feet will continue over the coastal waters into this evening. Later tonight as the low moves further offshore winds will gradually diminish and seas are expected to subside below 6 feet by early Thursday morning. NNE winds will cont at 10 to 15 knots Thu with some gusts to around 20 knots northern and central waters as high pressure builds north of the area. Seas will be mainly 3 to 5 feet Thursday...quite a bit lower over waters near the coast south of Cape Lookout. Long Term /Thursday Night through Monday/... As of 320 pm Wednesday...High pressure will build across the waters from the north Thursday night into Friday, moving offshore late Friday ahead of the next storm system. Southeast winds will quickly increase Saturday ahead of a cold front set to cross the waters Saturday Night/early Sunday. Winds expected to be around 15-25kts with higher gusts. Seas will build by Saturday afternoon, to around 6 to 8 feet across the central waters. Behind the front, winds shift northwesterly Saturday night into early Sunday with wind speeds 10-20 kts, helping to maintain seas 4 to 6 feet across the northern waters through late Saturday night. Winds shift northerly Monday but continue mostly 5-15 kt, yielding seas 3-5 ft north to 2-4 ft south. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 2 AM EDT Thursday for AMZ135-150- 156-158. Small Craft Advisory until 6 AM EDT Thursday for AMZ152-154. && $$ SYNOPSIS...RF NEAR TERM...RF/JBM SHORT TERM...RF LONG TERM...DAG/LEP AVIATION...JBM/DAG/SGK MARINE...RF/JBM/DAG
Area Forecast Discussion National Weather Service Raleigh NC 750 PM EDT Wed May 18 2016 .SYNOPSIS...In the wake of a departing low pressure system...a cool surface high pressure system will build over the area tonight through Thursday. A low pressure system tracking east across the Southern states will bring wet unsettled conditions to the Carolinas late Friday through early Saturday. && .NEAR TERM /through tonight/... As of 330 PM Wednesday... A sfc wave continues to linger off the SE coast of NC this afternoon. This feature will drift farther offshore tonight...being pushed along by a s/w in the northern stream crossing southern new england. In its wake...a weak shear axis and attendant inverted sfc trough will drift east into western NC tonight/early Thu. This feature interacting with abundant low level moisture may trigger a few showers in the vicinity of the Yadkin River late this evening through the overnight. Widespread cloud cover will limit the normal nocturnal cooling. Min temps low-mid 50s north half with upper 50s south. && .SHORT TERM /Thursday and Thursday night/... As of 330 PM Wednesday... WRF models along with a few near term models have trended wetter than previous runs for Thursday...apparently keying on the weak shear axis and inverted sfc trough. The WRF models are likely overdone considering they are overplaying the rain showers this afternoon in vicinity of the higher terrain in western NC. While the GFS and ECMWF both depict the inverted sfc trough washing out...being replaced by a narrow ridge of high pressure...model guidance still depicting measurable rain over most of central NC on Thursday. Models may be keying on confluence along a west-to-east 850mb boundary in vicinity of highway 64. Cross sections, however, reveal that the lift, weak as it is, is confined to the lowest 8k ft or so of the atmosphere. Thus, having a tough time buying into the high end likely/low end categorical pops across the area for Thursday. Appears highest threat for measurable rain will be Thursday morning...and mainly confined to the far SW. After 16Z, rain chances should be no more than a chance and highest over the south. Extensive cloud cover and chances for precip will prevent temps from warming much above overnight low temps. High temps should vary from the low-mid 60s north to the lower 70s se. If rain is more extensive than forecast, high temp may end up being 3-5 degrees cooler. Weak isentropic upglide late Thursday night will yield spots of light rain...especially after 04Z and mainly over the sw third of the forecast area. Min temps generally in the mid-upper 50s. && .LONG TERM /Friday through Wednesday/... As of 230 PM Wednesday... Friday through Saturday: High pressure will be extending down the east coast to begin the long term period, with a cold air damming regime setting up over the region. At the same time, a short wave will be moving towards the area from the west and this will set the stage for a rather wet period. A couple of waves of low pressure are progged to track near/along the CAD boundary that will set up across the area. Precip chances will increase from west to east throughout the day on Friday, with the best time frame being Friday night/early Saturday morning. Given the high shear/low cape environment that is expected, the severe weather threat is expected to be rather low, especially given the poor diurnal timing. The bigger threat is going to be the heavy rain potential, where average rainfall amounts are expected to range from around an inch across the southeast to possibly around 2 inches or more across the Northwest Piedmont, which could cause some minor flooding in urban areas or poor drainage locations. The majority of the precip should shift off to the northeast throughout the afternoon on Saturday, although persistent cyclonic flow aloft will linger across the area and will result in mostly cloudy skies and possibly a lingering showers into Saturday night. Given the CAD regime, high temps should range from low/mid 70s across the southeast to the low/mid 60s across the northwest. Sunday through Wednesday: Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /00Z Thursday through Monday/... As of 750 PM Wednesday... Poor aviation conditions will continue overnight as low clouds persist in northeasterly flow. The areawide improvement to MVFR this afternoon should give way to at least IFR by 06z, with some lifr and rain/drizzle possible at KGSO and KINT by 12z. The light rain and drizzle is expected to shift east through the morning hours, though with some drier low-level air filtering in from the northeast, confidence in the coverage of precip is lower toward KRDU and KRWI. There should be some slow improvement of ceilings in the east by midday, to MVFR and possibly VFR at KFAY by Thursday evening. Abundant moisture will continue the threat of low ceilings through Friday night. A strong low pressure system and cold front will cross the region on Saturday, helping to scour low-level moisture and bring VFR conditions for Sunday into early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...WSS LONG TERM...KRD AVIATION...22
Area Forecast Discussion National Weather Service Wilmington NC 756 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build from the north overnight into Thursday. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 704 PM Wednesday...No significant changes required with the early evening updates as mostly cloudy skies prevail with local temperatures overnight very close to climatology for this time of May. No drivers for significant PCPN tonight aside from MCV perturbation showers west of I-95 after 3 AM. Low level saturation late tonight may materialize a patch or 2 of drizzle, but for most locations, measurable rainfall is not likely. With low cloud ceilings and nearly saturated low level air, temperature drops will be slow to evolve, settling in the upper 50s to lower 60s daybreak Thursday. A pocket of mist or fog cannot be ruled out overnight as well given the very damp regime in place near the surface. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 00Z...MVFR with brief improvement to VFR possible this evening before widespread MVFR/IFR returns with areas of fog possible overnight. Improvement to VFR on Thursday is expected with increasing chances for showers throughout the day. Though latest radar imagery remains fairly quiet this evening, satellite imagery continues to show broken to overcast coverage of low clouds allowing for widespread MVFR to prevail at the terminals. Trends do indicate the potential for brief improvement to VFR over the next few hours, before cloud coverage increases again overnight. This along with developing areas of fog will create MVFR/IFR through the early morning hours. Light and variable winds are expected. After daybreak, expect conditions to improve to VFR with increasing chances for showers into the afternoon hours. Northeasterly winds around 5 kts in the morning will become east-northeasterly in the afternoon around around 10 kts. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 704 PM Wednesday...`Exercise Caution" headline is needed for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly mellower wind-speeds over the SC waters precludes this headline. Caution headline valid until midnight tonight as wind trends ease this evening, as a low offshore of Cape Lookout moves NE away from the coast...thus a very brief cautionary period. Virtually no wave energy with wave periods greater than 7 seconds exists right now and all energy is tied to nearby winds...thus slightly steep and bumpy this evening for only 3-5 ft seas. Dominant wave periods will hold between 6-7 seconds overnight with little or no shower activity. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MJC SHORT TERM...DCH LONG TERM...III AVIATION...SGL
Area Forecast Discussion National Weather Service Wilmington NC 704 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build from the north overnight into Thursday. A warm front will lift across the region Friday...bringing an increasing chance of rain. A surface low and its attendant cold front will sustain wet conditions Saturday into very early Sunday. A drying trend is expected early next week with near to slightly below normal temperatures. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 704 PM Wednesday...No significant changes required with the early evening updates as mostly cloudy skies prevail with local temperatures overnight very close to climatology for this time of May. No drivers for significant PCPN tonight aside from MCV perturbation showers west of I-95 after 3 AM. Low level saturation late tonight may materialize a patch or 2 of drizzle, but for most locations, measurable rainfall is not likely. With low cloud ceilings and nearly saturated low level air, temperature drops will be slow to evolve, settling in the upper 50s to lower 60s daybreak Thursday. A pocket of mist or fog cannot be ruled out overnight as well given the very damp regime in place near the surface. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 18Z... Low clouds will be persistent through the period. However through the afternoon they may tend to occasionally break from IFR to MVFR. With the loss of daytime heating lower ceilings will become more favorable, though not all model guidance indicates such. Have opted to keep with the more pessimistic view which does in fact sock the area in with IFR overnight and show improvement to MVFR a few hours after daybreak Thursday. Any visibility restrictions will be minor, MVFR-ish. Little to no precipitation is expected. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 704 PM Wednesday...`Exercise Caution" headline is needed for the NC waters for N winds 15-20 KT and 4-5 FT seas. Slightly mellower wind-speeds over the SC waters precludes this headline. Caution headline valid until midnight tonight as wind trends ease this evening, as a low offshore of Cape Lookout moves NE away from the coast...thus a very brief cautionary period. Virtually no wave energy with wave periods greater than 7 seconds exists right now and all energy is tied to nearby winds...thus slightly steep and bumpy this evening for only 3-5 ft seas. Dominant wave periods will hold between 6-7 seconds overnight with little or no shower activity. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MJC SHORT TERM...DCH LONG TERM...III AVIATION...SGL
Area Forecast Discussion National Weather Service Wilmington NC 337 PM EDT WED MAY 18 2016 .SYNOPSIS... High pressure will build in from the north overnight. A stalled front will move north across the area Friday as a warm front. A surface low will pass over or just west of the area late Friday night and drag a cold front across the area Saturday. Showers and thunderstorms are likely ahead of the front. Clouds and showers may linger on Sunday under low pressure aloft. The low will slowly move away from the area Monday through Wednesday with dry and seasonable conditions returning by the middle of next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 3 PM Wednesday...Models are in a decent consensus with sfc ridging from the north dominating thru early fri, with the highs center moving from the great lakes on Thu, to the NE States by early Fri. For Fri thru Fri night is when models detour from one another with respect to the eventual inland movement of the coastal front. Some mid and upper level drying early Thu will slowly moisten thruout the atm column by late Thu. Overrunning type pcpn will begin mid to late day Thu and persist thru Thu night into daytime Fri. some timing issues will exist afterwards from Fri aftn thru Fri night with regard to the coastal front lifting inland and eventually northward across the ilm cwa. Thu thru early Fri pcpn will be limited to mainly overrunning type pcpn with embedded heavier showers possible. Any thunder will remain south and east of the ILM CWA closer to where the frontal boundary lies and to where it bends inland over southern SC. For daytime Fri thru Fri night...the ILM CWA will be subject to heavier pcpn with overrunning light showers/rain dominating initially. As the coastal front pushes inland and at the same time lifting northward, the fa will find itself in the warm sector by daybreak sat. thus, convective type pcpn will eventually become the dominant type. this will also be reflected within the qpf fields. Stayed with a consensus of available model mos guidance thru daytime Fri...which basically keeps mid to upper 70s for highs, and upper 50s inland to low 60s at the coast for lows. For Fri night, the fa will see widespread 60s to near 70 at the coast for Sat lows. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a system emerging from the deep south moves northeast and up the coastal plain. This will bring increasing chances of rain on Friday after minimal chances on Thursday. We could see isolated thunder on Friday night as the low pressure system and an associated deepening upper trough move over the central Carolinas. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Period begins with surface system exiting to the north and 5h trough moving in from the west. Precip ongoing Sat morning will come to an end during the afternoon as west to northwest flow aloft advects in much drier air. PWATs drop from near 2 inches AM Sat to near 1.25 inch late Sat afternoon. Arrival of dry air combined with low level subsidence will bring an end to the rainfall. Mid level trough lingers over the area for the weekend, briefly becoming cutoff Sun into Mon. Some disagreement between the latest GFS/ECMWF as to the placement of the 5h cutoff but it will be close enough to ensure temps below climo, cloudy skies, and possibility of isolated afternoon instability showers Sun. Troughing will remain over or just off the east coast through the end of the period, keeping unsettled weather close by. However, precip chances should diminish quickly Mon as deep northwest flow aloft develops. Temps a little below climo Mon climb near climo Tue and above climo Wed as weak mid level ridge starts to build over the southeast. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... As of 18Z... Low clouds will be persistent through the period. However through the afternoon they may tend to occasionally break from IFR to MVFR. With the loss of daytime heating lower ceilings will become more favorable, though not all model guidance indicates such. Have opted to keep with the more pessimistic view which does in fact sock the area in with IFR overnight and show improvement to MVFR a few hours after daybreak Thursday. Any visibility restrictions will be minor, MVFR-ish. Little to no precipitation is expected. Extended Outlook...VFR Thur before convection and possible MVFR/IFR return Fri through Sun. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes Thursday morning will push east to the NE States by Fri, and off the NE States Coast Fri night. Sfc ridging from the highs center will extend south/down the east coast. at the same time, a stalled frontal boundary or coastal front will lie just offshore and parallel to the ILM CWA coastline, before bending back westward and inland in the vicinity of the SC and GA Border. As a result, the local waters will be subject to a ne-ene wind direction thru early Fri. A somewhat tightened sfc pg will exist thruout the period, with wind speeds generally in the 10 to 20 kt range. From midday Fri thru Fri night...the frontal boundary offshore and south of the area waters...will push inland and lift northward at the same time. This boundary is expected to push inland during Fri night with winds veering from the e to se Fri Evening...and further veering to the South by daybreak Sat. Wind speeds will remain 10 to 20 kt especially after the front pushes onshore. Significant seas will mainly be a function of wind driven waves, with dominating periods increasing from 4 to 5 seconds early Thu to 6 to 7 seconds on Fri. Sea Heights will likely reach SCEC Thresholds Thu Night, and possibly SCA Thresholds during Fri. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...High pressure centered over the Great Lakes on Thursday morning pushes east over the mid-Atlantic states by Friday morning as a low pressure system emerging from the deep south moves northeast and up the coastal plain. The pressure gradient will not really tighten much until this system approaches the Carolinas, so expect only a modest 10 to 15 kt wind range with seas of 2 to 4 ft until then. Seas will increase to 3 to 5 ft Friday night as winds gradually increase with the approach of the low pressure system. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Strong southerly flow at the start of the period will become west to northwest later Sat and Sat night following the passage of a cold front. Surface high will build in behind the front Sun and Mon with flow out of the north through the end of the period. Postfront Cold advection and pressure gradient are of limited strength. Ahead of the cold front southerly flow will be 15 to 20 kt but following the passage of the front speeds will be be in the 10 to 15 kt range. Seas as high as 5 ft will be possible Sat ahead of the front but development of offshore flow combined with decreased wind speeds will drop seas to 3 to 4 ft Sun and 2 to 4 ft Mon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...DCH SHORT TERM...DCH LONG TERM...III AVIATION...MBB
Area Forecast Discussion National Weather Service Newport/Morehead City NC 324 PM EDT WED MAY 18 2016 .SYNOPSIS... Low pressure off the coast will continue to move northeast away from the area tonight. High pressure will extend into the area from the north Thursday and Friday. Low pressure will develop to the southwest late Friday night then lift northeast across the region Saturday. The low will lift northeast of the area Saturday night and Sunday pushing a cold front offshore. Low pressure will develop well offshore early next week as high pressure builds south of the region. && .NEAR TERM /THROUGH TONIGHT/... As of 230 PM Wednesday...Rain has rapidly diminished across the region and will lower pops to slight chc thru early evening with patchy light rain or drizzle...mainly near coast. Any lingering precip should end by mid evening as drier mid level air spreads in. Low levels will remain nearly saturated and expect good deal of clouds to persist thru the night. Lows will be mainly in the mid to upper 50s...poss holding around 60 central/southern beaches. && .SHORT TERM /THURSDAY/... As of 230 PM Wednesday...High pressure will build N of the area with mainly dry weather expected. Bulk of models do show some increase in moisture and light qpf SW tier late ahead of weak short wave so added slight pop this area. Plenty of clouds will continue over the region and with NNE surface flow temps will remain cool with highs low/mid 70s with some 60s Outer Banks. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As of 3 pm Wednesday...A very active weather pattern with below normal temps through a portion of the period. Thursday Night through Friday Night: High pressure will migrate eastward through the Mid-Atlantic states during the period, eventually moving offshore by early Saturday. North flow will start to veer easterly Friday as the surface high shifts offshore. Southeast flow increases Friday night as the next storm system approaches from the southwest. Introduced slight chance pops Thursday night into Friday for the southerly third of the CWA as a weak boundary remains south of the area with moisture lingering. PWATS increase rapidly Friday afternoon/evening as southwesterly flow in the mid levels brings in greater moisture across the area. Precip chances increase from slight chance late Friday to likelies late Friday night, partly due to a warm front lifting north through the region. Temps Friday will range low/mid 70s due to precip/clouds. Thursday night lows will range in the mid 50s to near 60 along the OBX, and mid/upper 60s areawide on Friday night. Saturday through Monday: A developing surface low will shift northeast through Eastern NC on Saturday as an upper trough digs southeast from the Great Lakes into the Mid-Atlantic region. This will result in a surface low developing/moving north of the area Saturday with a cold front crossing Saturday afternoon/evening. Given we will be under the warm sector ahead of the front with ample lift, moisture and sufficient instability/shear, the convective potential looks probable, especially in the afternoon. The timing of this front and the subsequent cloud cover will be a big factor in the severity/coverage of any storms that develop. It is a bit far out to iron out details at this point, but looks like the front crossing around late afternoon will limit convection in the evening. The surface low will move off the Mid- Atlantic coast Sunday with the closed upper low becoming anchored across the Eastern CONUS through midweek. This will then provide continued cloud cover and slight chance showers through the remainder of the period. Temps will remain in the low/mid 70s during this period, with the cooler day being Sunday after the front crosses and a surge of cooler air moves into the region. Tuesday through Wednesday: The closed upper low will finally lift northeast into New England with zonal flow developing by Wednesday. Meanwhile, high pressure quickly builds in, shifting offshore by Wednesday ushering in warm return flow and more seasonable temperatures. High temps Tuesday will be in the upper 70s and rebound into the low/mid 80s by Wednesday. Given moisture return and modest instability, introduced slight chance showers and thunderstorms for Wednesday afternoon for inland sections. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... Short Term /Through Thursday Afternoon/... As of 145 pm Wed...IFR conditions are present across the region due to ceilings just under 1000 feet. Expecting ceilings to rise another couple hundred feet this afternoon...which will raise conditions to MVFR. However IFR ceilings will return after or near midnight with continued northeast flow and trapped low level moisture. LIFR conditions could be met early Thursday morning but will hold off on mentioning them in the TAF for this issuance. Fog looks unlikely due to a lingering light breeze overnight but patchy fog cannot be ruled out. VFR conditions should return after 8 or 9 am Thursday under continued cloudy skies. Long Term /Thursday Night through Monday/... As of 310 pm Wednesday...High pressure to the north will persist through Friday, then eventually shifts offshore Friday Night. Expect VFR conditions through Friday, with some mid level clouds returning Thursday night through Friday especially for OAJ/EWN. With return flow quickly developing Friday afternoon and the increase in precipitation, expect lowering ceilings with sub-VFR conditions likely. Ample moisture will be present Friday night through much of Saturday ahead of a front that is progged to cross later Saturday. Lingering sub-VFR conditions can be expected early Sunday. Drier air will work its way into the region through the remainder of Sunday and into Monday. However, do expect lingering mid/upper level clouds Sunday under north flow. Predominant VFR expected Monday. && .MARINE... Short Term /Tonight and Thursday/... As of 230 PM Wednesday...NNE winds remain quite gusty along the coast to N and W of low pressure located SE of Cape Lookout. Winds should remain up along the coast into the evening before diminishing overnight as low departs. Seas of 5 to 8 feet will continue over the coastal waters into this evening. Later tonight as the low moves further offshore winds will gradually diminish and seas are expected to subside below 6 feet by early Thursday morning. NNE winds will cont at 10 to 15 knots Thu with some gusts to around 20 knots northern and central waters as high pressure builds north of the area. Seas will be mainly 3 to 5 feet Thursday...quite a bit lower over waters near the coast south of Cape Lookout. Long Term /Thursday Night through Monday/... As of 320 pm Wednesday...High pressure will build across the waters from the north Thursday night into Friday, moving offshore late Friday ahead of the next storm system. Southeast winds will quickly increase Saturday ahead of a cold front set to cross the waters Saturday Night/early Sunday. Winds expected to be around 15-25kts with higher gusts. Seas will build by Saturday afternoon, to around 6 to 8 feet across the central waters. Behind the front, winds shift northwesterly Saturday night into early Sunday with wind speeds 10-20 kts, helping to maintain seas 4 to 6 feet across the northern waters through late Saturday night. Winds shift northerly Monday but continue mostly 5-15 kt, yielding seas 3-5 ft north to 2-4 ft south. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 2 AM EDT Thursday for AMZ135-150- 156-158. Small Craft Advisory until 6 AM EDT Thursday for AMZ152-154. && $$ SYNOPSIS...RF NEAR TERM...RF SHORT TERM...RF LONG TERM...DAG/LEP AVIATION...DAG/SGK MARINE...RF/DAG
Area Forecast Discussion National Weather Service Raleigh NC 237 PM EDT Wed May 18 2016 .SYNOPSIS...In the wake of a departing low pressure system...a cool surface high pressure system will build over the area tonight through Thursday. A low pressure system tracking east across the Southern states will bring wet unsettled conditions to the Carolinas late Friday through early Saturday. && .NEAR TERM /through tonight/... As of 1030 AM Wednesday... Upper air analysis depict a weak low level trough over the ne sector of central NC. Weak confluence along this boundary in conjunction with modest lift aloft associated with divergence in the right entrance region of a 110+ kt jet exiting the northern Mid-Atlantic was causing spots of light rain/drizzle across sections of central NC this morning. The patches of light rain/drizzle will diminish with time and lift becomes weaker. Abundant low level moisture will be tough to scour out due to lack of sufficient mixing of drier air...thus a blanket of low stratus will persist into the afternoon hours. Area MDCRS aircraft soundings suggest the cloud thickness about a 1000ft or a little less. This suggest that some breaks may occur late in the day...though likely too late to add in temp recovery. Low overcast skies and a steady near sfc ne wind will hold temps well below normal for mid-May. Afternoon temps will top out in the mid-upper 60s north to near 70-lower 70s south. -WSS Ceilings are expected to quickly fall/lower after sunset with IFR to LIFR conditions expected everywhere overnight. Continued weak upglide along the eastern slopes of the mtns will continue to support a slight to small chance of rain, mainly across the western Piedmont. Lows tonight in the lower 50s north to upper 50s south. -CBL && .SHORT TERM /Thursday and Thursday night/... As of 345 AM Wednesday... Parent high center will build over the Mid-Atlantic Seaboard on Thursday with low-level wedge of cooler and drier air ridging south into the area underneath continued WSW flow aloft, within the right entrance region of a ~90kt upper jet streak in place over the Mid- Atlantic region. Low clouds/moisture will persist but sufficient forcing is absent over the area during the day on Thursday. So expect a gray gloomy day across the area with continued below normal temperatures in the mid/upper 60s north to lower 70s south. Weak upglide begins to strengthen Thursday night, in response to mid- level shortwave trough and sfc cyclogenesis over the lower MS/TN Valleys. Better rain chances will remain to our west but will continue to indicate isolated/slight chance pops across the far southern/southwestern zones with onset of In-situ Damming expected. Lows again in the lower 50s to upper 50s, coolest ne. && .LONG TERM /Friday through Wednesday/... As of 230 PM Wednesday... Friday through Saturday: High pressure will be extending down the east coast to begin the long term period, with a cold air damming regime setting up over the region. At the same time, a short wave will be moving towards the area from the west and this will set the stage for a rather wet period. A couple of waves of low pressure are progged to track near/along the CAD boundary that will set up across the area. Precip chances will increase from west to east throughout the day on Friday, with the best time frame being Friday night/early Saturday morning. Given the high shear/low cape environment that is expected, the severe weather threat is expected to be rather low, especially given the poor diurnal timing. The bigger threat is going to be the heavy rain potential, where average rainfall amounts are expected to range from around an inch across the southeast to possibly around 2 inches or more across the Northwest Piedmont, which could cause some minor flooding in urban areas or poor drainage locations. The majority of the precip should shift off to the northeast throughout the afternoon on Saturday, although persistent cyclonic flow aloft will linger across the area and will result in mostly cloudy skies and possibly a lingering showers into Saturday night. Given the CAD regime, high temps should range from low/mid 70s across the southeast to the low/mid 60s across the northwest. Sunday through Wednesday: Models are still showing a shortwave trough digging down from Canada and eventually forming a closed upper low off the coast early next week. There is still some uncertainty on the exact location of this feature, which will have implications on our precip chances. As of right now, it looks like precip chances will remain in the isolated to widely scattered range and especially during the day coincident with day time heating. Conditions should dry out going into Tuesday and Wednesday as the upper low begins to pull away. Temps will gradually moderate through the period, from mostly low 70s on Sunday to mid 80s by Wednesday. && .AVIATION /18Z Wednesday through Monday/... As of 120 pm Wednesday... There is a high likelihood that mvfr/ifr ceilings will persist across central NC through tonight. In addition, there will be pockets of mvfr/ifr fog developing after 05Z. Spots of light rain will be possible in vicinity of the Triad terminals toward daybreak...possibly heading into the KRDU vicinity by mid morning. Abundant low level moisture will maintain a deck of low clouds across central NC through early friday...and possibly through Saturday morning. A pair of weak low pressure systems will increase the threat for rain showers across central NC. The initial wave will bring an enhanced threat for showers late Thursday night to the southern counties including the KFAY vicinity. The later wave...forecast to be stronger...will increase the threat for showers across most of central NC Friday night into Saturday morning. Improving aviation conditions are expected by late Saturday...with a good probability of vfr conditions Sunday and Monday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...wss NEAR TERM...WSS/CBL SHORT TERM...CBL LONG TERM...KRD AVIATION...wss Area Forecast Discussion National Weather Service Taunton MA 418 PM EDT THU MAY 19 2016 .SYNOPSIS... Low pressure aloft rides over the top of high pressure at the surface to bring scattered afternoon and evening showers with isolated thunderstorms to Southern New England today. High pressure regains control later tonight and brings dry mild weather Friday and much of Saturday. The high gives way to some rain especially across the south Saturday night into Monday. Cooler and unsettled conditions linger into early next week before warmer weather returns mid week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 4 PM update... Vortex/mid level low over Upstate NY into VT this afternoon providing cyclonic flow aloft across Southern New England along with 500 mb temps falling to -23C into Western-Central MA at 4 pm. This combination of lift and instability is resulting in scattered showers and isolated thunder with convection focused across the hilly terrain. The anomalous cold air aloft resulting in low freezing levels and wet bulb zero heights. This will yield a low risk for a few storms to produce small hail. Already received a report of pea size hail at 240 pm in Westhampton MA. In addition, with surface temp/dew pt spreads on the order of 20 to nearly 30 degs...this will result in an inverted-v sounding and result in a risk of gusty winds as well. Convection will continue to advect eastward and reach RI and Eastern MA around 5ish but may not advance much farther South and East than a Boston to Providence line as low level lapse rates ease in response to marine layer along with sunset. Thus scattered showers and isolated thunder will be focused northwest of the I-95 corridor. As the evening progresses, convection dissipates and skies will clear from northwest to southeast. Not much of an airmass change behind this convection so expecting temps to be seasonably cool overnight. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Friday... Real gem of a day with temps soaring well into the 70s away from the shore, as a weak WNW pressure gradient allows afternoon sea breezes to develop, keeping the shoreline in the 60s to near 70. As mid/upper trough moves offshore mid level flow becomes anticyclonic providing dry weather and sunshine. However SCT-BKN diurnal CU/STRATO-CU will develop by late morning into the afternoon. Nevertheless partial sunshine, light winds and temps in the 70s with dewpoints in the 40s will provide ideal mid to late May weather. Fri night... Mid level ridge crests over the region providing dry weather and seasonably cool temps with lows in the 40s except low 50s in the urban areas. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Highlights... * Dry and warm weather Saturday * A coastal low pressure system will bring rain Sat. night and Sun. * Unsettled weather continues through early next week * Temperatures warm up the middle of next week Models are in fairly good agreement, except for the 12Z GFS is a bit weaker and faster with low pressure moving up the east coast Saturday night and passing through the southern New England coastal waters Sunday morning. Because that creates a few timing issues later on in the forecast period, have discounted the GFS for much of this forecast. Saturday will be the pick of the weekend with mainly dry weather during the day and temperatures several degrees above normal for much of the area. Exceptions will be along the south coast, Cape,and Islands where onshore winds will keep temperatures a bit cooler along the immediate coast. The main story for this period of the forecast will be the coastal low passing by the region Sunday morning. The main problem with it is it actually doesn`t pass by but instead meanders around the Gulf of Maine and New England until Tuesday when it finally moves off into the Maritimes. Therefore, we will have unsettled weather with periods of rain and showers with cooler than normal temperatures for Sunday and Monday and part of Tuesday as well. There is some marginal instability Sunday and Tuesday so we could see some stronger showers and even a few thunderstorms, but there is still quite a bit of uncertainty. As the low pressure finally moves into the Maritimes, high pressure is allowed to build into southern New England briefly Wednesday. Southwesterly winds will bring much warmer air into the region and temperatures will soar a good 10 degrees above normal. Thursday, another weak low pressure system will move over the area bringing another chance of rain. However, temperatures will warm even a few degrees above Wednesday. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday Night/... 2 PM update ... Thru 00z...High confidence on trends but some uncertainty how far south and east showers and isolated thunderstorms track. Activity may struggle to reach BOS-PVD and points SE. Mainly VFR but brief MVFR in scattered showers and isolated thunder. A few of the stronger cells may contain small hail and gusty winds with greatest risk across the higher terrain. Light east to southeast winds across RI and eastern MA. Elsewhere, light and variable becoming light westerly. After 00z...High forecast confidence. Mainly VFR with any lingering MVFR showers and isolated thunder ending between 01z and 03z. Light and variable winds becoming light WNW. Friday...High forecast confidence. VFR and dry weather. Diurnal clouds develop but will be in the VFR category. Light WNW winds but sea breezes may develop along the coast. Friday night...High forecast confidence. VFR...dry weather and light winds. KBOS TAF...High confidence. Scattered showers and isolated Thunder approach Logan/s airspace after 21z. However most activity will be focused to the west across the Worcester Hills. Winds remain mostly easterly. KBDL TAF...High confidence. Scattered showers and isolated thunder. Low risk for a few storms containing small hail and gusty winds thru 22z. Outlook...Saturday through Tuesday... Saturday...High confidence. VFR conditions to start. Conditions deteriorate late in the day and during the overnight as clouds increase and rain begins. MVFR/IFR conditions likely in rain overnight. Sunday...Moderate confidence. MVFR/IFR conditions will improve quickly to VFR except perhaps along the Cape and Islands where rain and clouds will be slower to pull away from the region. Monday...Moderate confidence. A mix of conditions expected with low clouds backing back into the east coast from a coastal low pressure system. Western areas may see VFR conditions while the east coast has MVFR or even IFR conditions for a period Monday. Tuesday...Moderate confidence. Conditions improve all around as low pressure finally pulls away from southern New England. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight...High forecast confidence. Light and variable winds become WNW after midnight. A few showers and/or isolated thunder near shore into early evening. Otherwise dry weather and good vsby. Friday...High forecast Confidence. High pressure provides light wnw winds in the morning then becoming light and variable. Dry weather and good vsby. Friday night...High forecast Confidence. More of the same...high pressure overhead provides light winds/dry weather and good vsby. Outlook /Saturday through Tuesday/... Saturday...High confidence. Low pressure moves northeastward from North Carolina up into our coastal waters late Saturday night. This will result in an increase in winds and seas. Small craft advisories may be necessary on the outer waters. Sunday and Monday...High confidence. Low pressure slowly moves eastward out of the coastal waters, but seas and winds will remain elevated through much of the time period. Small craft advisories are likely. Tuesday...High confidence. High pressure starts to build back in over the waters. This will allow winds and seas to subside below small craft levels. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Nocera/RLG NEAR TERM...Nocera SHORT TERM...Nocera LONG TERM...RLG AVIATION...Nocera/RLG MARINE...Nocera/RLG
  [top] Area Forecast Discussion National Weather Service New York NY 354 PM EDT THU MAY 19 2016 .SYNOPSIS... High pressure builds over the region on Friday. An unsettled weather pattern sets up this weekend and remains into early next week. High pressure builds in for the middle of next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... a few sprinkles are falling from the stratocumulus over the interior, but overall the RAP and HRRR PCPN fields have been extremely over done all day. Have kept an isolated -SHRA for interior Southern CT as the upper low cold pool passes across New England. Otherwise, skies clear with loss of daytime heating. overnight lows are a blend of MOS - which has little spread. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... SKC on Friday. Highs in the 70s. An afternoon sea breeze develops at the coast. Temperatures are again from a blend of the MOS that had little spread. Clouds increase Friday night with warm advection aloft. Clouds keep minimums about a few degrees warmer than tonight. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Unsettled pattern through early next week. Models in decent agreement with northern and southern stream shortwave energy over the Central US/Canadian plains phasing over the Great Lakes/Ohio Valley Fri Night/Sat and then swinging to the east coast as a closed low Sat Night into Sun. Models continue to exhibit spread in the exact timing and location of cutoff upper low development, which SBU sensitivity analysis indicates the spread may be related to downstream effects from the large upper low over the NW US and subsequent northern/southern stream shortwave phasing. This is manifesting in increasing track differences with an associated southern low as it tracks from the Mid-Atlantic coast on Sat and then se of the region Sat Night into Sun....and the resultant placement of frontogenetic rain banding to the north of the low. Higher probability at this point is for the heavier rain banding to stay to the south...but enough large scale lift for lighter rain to work into the region Sat into Sat night. SBU sensitivity indicates there is a chance for this heavier rain to track farther north. With the stated uncertainty have stayed close to gefs/cmc/sref ensembles qpf probabilities for greater than .05 inches for pops...with likely for southern portions of the tri- state and chance north. General agreement with low pressure tracking ne into the Gulf Of Maine on Sunday...with steady rain coming to an end Sat night into Sun Morning. Thereafter...general agreement with the closed low sitting over the northeast Sun into early next week in an omega blocked pattern. So although coastal low pressure will track offshore...the region will remain in an unsettled pattern under the cold pool of the upper low and weak surface troughing Sun afternoon through Tuesday afternoon. This will bring considerable daytime cloud cover with diurnal instability shower activity each afternoon. There is a chance for isolated tstms as well. Shower activity at night will be tied to any vorts tracking over the region. With dewpoints creeping up each night, may be dealing with stratus/fog issues each night as well. Daytime highs during this period will likely be near to slightly below seasonable...and near seasonable for highs. Signs that omega blocking breaks down by midweek with rising height and deep wsw flow. If this occurs...this would finally bring drier weather and moderation to above normal temperatures. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... VFR through the TAF period. Broken ceilings around 6000-10000ft this evening will become scattered. Light onshore winds near 10 KTs at coastal terminals this evening will diminish and become light and variable around 5 KTs tonight. On Friday...mainly nw flow is expected around 10-15 KTs. A coastal sea breeze is possible at KJFK and KISP due to light gradient. NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments are expected. KLGA TAF Comments: No unscheduled amendments are expected. KEWR TAF Comments: No unscheduled amendments are expected. KTEB TAF Comments: No unscheduled amendments are expected. KHPN TAF Comments: No unscheduled amendments are expected. KISP TAF Comments: No unscheduled amendments are expected. .OUTLOOK FOR 20Z FRIDAY THROUGH TUESDAY: .20z Friday and Friday night...VFR. .Saturday-Sunday...MVFR or lower possible in rain...depending on exact track of coastal low. Best chance is at NYC and Long Island Terminals. NE-N winds G20-30kt possible. .Sunday Night-Tuesday...Most likely VFR. However, cannot rule out a few showers with possible MVFR conditions.&& .MARINE... Sub-advsy conds are forecast through Fri night with the area in a weak pres gradient regime. Next chance for SCA conditions will be with coastal low pressure tracking to the southeast of the region Sat into Sat night. Still some uncertainty with track of this low, but potential for sca winds exists for at least ocean and eastern waters with accompanying sca seas on the ocean Sat night into Sun morning. Sca ocean seas may linger through Sun with residual se swells. Sub sca conditions should return for early next week with region under weak pressure gradient regime. && .HYDROLOGY... Dry until Fri night. Sat into early Sun Morning, 1/4 to 1/2 inch of rain is likely for NYC/NJ metro, LI, and SE CT; with up to 1/4 inch to the north. There is potential for 1/2 to 1 1/4 inches of rain if low pressure tracks farther north, with highest amounts across southern portions of the tri-state. Additional rainfall is possible Sunday through Tuesday with no hydrologic impacts expected. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Tongue NEAR TERM...Tongue SHORT TERM...Tongue LONG TERM...NV AVIATION...IRD MARINE...Tongue/NV HYDROLOGY...NV
Area Forecast Discussion National Weather Service Taunton MA 205 PM EDT THU MAY 19 2016 .SYNOPSIS... Upper level low pressure rides over the top of surface high to bring scattered afternoon and evening showers with isolated thunderstorms to Southern New England today. High pressure regains control later tonight and brings dry mild weather for Friday and much of Saturday. The high gives way to some rain especially across the south Saturday night into Monday. Cooler and unsettled conditions linger into early next week. && .NEAR TERM /THROUGH TONIGHT/... 2 PM update... Convection beginning to fire inland especially across the high terrain closer to the cold air aloft. Weak convergence across the CT river valley helping to sustain convection with light easterly flow from Worcester Hills eastward...while light westerly winds at ORE/PSF and AQW. As mentioned in previous discussions magnitude of cold air aloft (-23c at H5 already into Northwest MA) will support a risk for a few small hailers. Meanwhile temp/dew pt spreads of 20-25 degs will support the risk for gusty winds in the stronger cells. Greatest risk for thunder/small hail and gusty winds will be across the higher terrain such as the Worcester Hills and East Slopes of the Berkshires. Convection probably doesn/t reach RI and Eastern MA until 5 pm or later. Showers and isolated thunder may dissipate before reaching the coastline of RI and MA as instability wanes toward sunset. Otherwise typical mid May day with highs in the upper 60s to lower 70s away from cooling seabreezes where the shoreline remains in the upper 50s to low 60s. Earlier Discussion... Today... Upper low pressure over the St Lawrence Valley with supporting upper jet along the Mason-Dixon Line. Left exit region of the jet lines up over Southern New England. Upper low and associated cold pool will move east with the core of cold air over Northern New England, but noticeable cooling aloft over Southern New England with temps aloft reaching -22c to -24c. This along with some daytime heating of the surface will create sufficient lapse rates and instability to support rising air. The rising air will have sufficient moisture to generate showers. Stability values will be low enough to suggest a few tstms. Wet bulb zero values around 6500 feet and cold temps higher up would suggest possible small hail. Can/t rule out strong wind gusts but confidence in wind is very low. Forecast chance pops for showers/tstms and will mention small hail. Daytime heating will also help generate sea breezes on all coasts starting later this morning through the afternoon. Mixing is indicated to reach 800 mb. Temps at that level would support max surface temps in the mid to upper 60s. With enough sun the mixing could go a little higher and generate slightly higher max temps. We will aim at the mid 60s to lower 70s with cooler values on parts of Cape Cod and Islands. && .SHORT TERM /FRIDAY/... Tonight... Cold pool aloft lingers overhead through the first part of the night. Even with nighttime cooling this should maintain some instability during early night. Continue scattered showers/tstms before midnight. The airmass then stabilizes and dries. This will mean clearing skies and an end to any showers. Not much of a change in the airmass and dew points will again be in the 40s. Therefore min temps expected in the 40s and lower 50s. Friday... High pressure surface and aloft will bring fair dry weather. Temperatures aloft will be about 6C milder than today and so the airmass will be more stable. Some lingering moisture around 800 mb should support some diurnal cumulus development but by itself not enough to support any showers except as noted below. Northwest winds are expected to be light. If so then the daytime heating may create another afternoon of sea breezes especially along the east MA coast. It is possible that convergence along a sea breeze front may be enough to set off a local shower. Daytime heating will again build the mixed layer to near 800 mb with temps at that level supporting max surface temps in the low to mid 70s. If mixing goes above 800 mb then some upper 70s may be possible. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Highlights... * Dry and warm Sat. * Unsettled late weekend and early next week. Overview and Model Preferences... Highly amplified flow pattern will progressively develop late this week and into the weekend. Weakly positive AO/NAO with strongly negative PNA are featured. The negative PNA is a reflection of slow moving, large and persistent cutoff which will remain over the Pacific CONUS through the period. Meanwhile downstream will be a gradually amplifying ridge continuing to deepen/dig trof downstream. This trof will be the defining feature for the sensible wx across our area through early next week, as it gradually deepens and cuts off completely. The ridge to the w will fold over the cutoff, locking it in place from late Saturday into early Tuesday. Therefore, after a quiet start to the weekend, an unsettled and occasionally wet pattern looks to follow. Reasonable synoptic-scale agreement here between operational models, so a blend of these will work initially, however ensembles still uncertain regarding the track of low pres Saturday night into Sunday, which will ultimately define who does and does not receive precipitation. Will lean more on a probabilistic approach here, using ensemble probabilities to help finalize pop/temps. Details... Fri night into Sat... Weak ridge of high pres gains control Fri and then quickly loses it on Sat as upper lvl cutoff begins to develop thanks to phasing of N and S streams. Final period of definite dry wx expected yielding cool min temps /thanks to radiational cooling/ Fri night, and warm highs on Sat. Only risk here is that highs may under-achieve a bit on Sat especially further S as increasing clouds may limit mixing from fully realizing the H85 temps around +8C. Still, will feature highs in the low-mid 70s across much of the area. Sat night into Sun... Low pres looks to pass S of the 40/70 benchmark during the early AM hours on Sun morning. How far N the precip shield ultimately reaches will be a factor of this exact track and the drier/cold advection settling in from the N. ECENS/GEFS ensemble probabilities are highest /50-70 percent range/ mainly along the immediate S coast then dropping to about 30 percent at the Mass Pike. Will yield pops quite near these numbers given the envelope of solutions between both the operational and ensemble guidance. In any case modest NNE flow develops on Sun, locking in some of the low lvl moisture off of the Gulf Of Maine and yielding colder than normal temperatures for much of the region. Expect clouds to remain in place much of the day thanks to this onshore flow. Even with the cloud cover, indications for instability trof to develop during peak heating Sun afternoon which may spawn some more showers and possibly even a rumble of thunder or two. Especially over the interior, where TT reach near 50 and H5 temps drop quite close to -20C. At odds will be the lack of sfc based instability with NNE flow, but feel there is enough moisture/instability to feature another round of shra later in the day Sun. Mon and Tue... Cutoff remains in place across much of New England through the early half of the next work week. Although it will warm aloft and gradually fill, the combination of colder H5 temp anomalies, leftover moisture and cyclonic flow will yield unsettled period especially defined by diurnal warming. Still not a washout here, as there are likely to be periodic breaks between the shra/ra risk. Overall temps show variance in the mid lvls and will likely be dependent on cloud cover and final precipitation coverage. Will mainly go near to slightly below seasonal. Mid next week... Cutoff to progressively shift E so depending on timing, suspect there will be a transition to drier and warmer conditions as it does so. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday/... 2 PM update ... Thru 00z ... high confidence on trends but some uncertainty how far south and east showers and isolated thunderstorm track. Activity may struggle to reach BOS-PVD and points SE. Mainly VFR but brief MVFR in scattered showers and isolated thunder. A few of the stronger cells may contain small hail and gusty winds with greatest risk across the higher terrain. Light East to Southeast winds across RI and Eastern MA. Elsewhere light and variable becoming light westerly. After 00z ... high forecast confidence. Mainly VFR with any lingering MVFR showers and isolated thunder ending between 01z and 03z. Light and variable winds becoming light WNW. Friday ... high forecast confidence. VFR and dry weather. Diurnal clouds develop but will be in the VFR category. Light WNW winds but seabreezes may develop along the coast. Friday night ... high forecast confidence. VFR...dry weather and light winds. KBOS TAF ... High confidence. Scattered showers and isolated Thunder approach Logan/s airspace after 21z. However most activity will be focused to the west across the Worcester Hills. Winds remain mostly easterly. KBDL TAF ... High confidence. Scattered showers and isolated thunder. Low risk for a few storms containing small hail and gusty winds thru 22z. Outlook...Sat into Monday Saturday...High Confidence. Mainly VFR with winds WSW. Sat and Sun...Moderate Confidence. Periods of MVFR/IFR possible through the period with rain/showers possible as low pressure churns to the south. This will be intermingled with some VFR conditions as well. Northeast winds expected. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today... High confidence. Light winds and seas. There is a potential for a few light showers or isolated thunder moving off the land mid to late afternoon. Tonight... High Confidence. High pressure rebuilds over the waters. Any early night showers or thunderstorms will quickly dissipate. Winds and seas will remain below 15 knots and 5 feet. Friday... High Confidence. High pressure over the waters. Winds remain below 15 knots and seas below 5 feet. Outlook /Friday Night through Monday/... Fri Night into Sat...High Confidence. High pressure spills over the waters and allows for a period of mainly quiet boating weather. Sun and Mon...Moderate Confidence. Low pres south of the region will bring a period of rain, especially across the southern waters. Northeast winds will gust to around 25 kt at time Sun, while a building swell reaches 5-6 ft and lingers into Mon. Small craft advisories are likely to be needed. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...WTB/Doody NEAR TERM...WTB/Nocera/Doody SHORT TERM...WTB LONG TERM...Doody AVIATION...WTB/Nocera/Doody MARINE...WTB/Nocera/Doody
  [top] Area Forecast Discussion National Weather Service Albany NY 153 PM EDT THU MAY 19 2016 .SYNOPSIS... An approaching upper level disturbance will allow for increasing clouds with a chance for some showers and possibly a thunderstorm today with seasonable temperatures. Although warmer temperatures with plenty of sunshine is expected on Friday, there will be chance for showers over the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1257 PM EDT...Clouds continue to build mainly across the higher terrain with daytime heating and cold pool aloft. Mohawk/Hudson valleys remain partly/mostly sunny, while most mountain areas are already mostly cloudy. Scattered showers with isolated thunderstorms will continue to develop this afternoon and will be most prevalent across the higher terrain areas especially north and east of Albany in the Adirondacks, southern Green Mountains of VT and the Berkshires. Will continue to mention isolated thunderstorms with small hail as a closed upper low and its associated cold pool move over the region. SPC mesoanalysis from Noon indicate the steepest mid level lapse rates of at least 6.5C/km located north of the Capital District and Mohawk valley, so main threat for small hail will be over the Adirondacks and southern Greens. SBCAPE values may reach 250-500 J/Kg, but likely not much greater due to limited heating and low level moisture. Wet bulb zero values are between 4000 and 6500 ft with h7 temperatures are -6 to -8 C. Highs today will range from the upper 50s northwest to the lower 70s southeast. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... Tonight, the upper level low pressure system will drift across northern New England and into the Canadian Maritimes bringing an end to the shower activity this evening with clearing skies late this evening. It will be a rather chilly night with lows ranging from the upper 30s northwest to the mid 40s southeast. On Friday a large ridge of high pressure will build across the region from the eastern Great Lakes. Expect Sunny skies and mild conditions with highs ranging from the upper 60s northwest to mid 70s southeast. Friday night will be still be dry with mainly clear skies during the evening giving way to increasing clouds late at night. Lows Friday night will be in the 40s to around 50. The numerical guidance is in fairly good agreement in bringing a low pressure system up the eastern seaboard Saturday and Saturday night. The question as is usually the case is how close to the coast does this system track. The NAM, GGEM and ECMWF all develop a closed low passing off the southern New England coast by Sunday morning, whereas the GFS maintains an open wave with just the passage of a frontal boundary. Will side with models that have a closed circulation and therefore place the highest pops across the southeast portion of the fa keeping the northwest third of the fa mainly dry. On Saturday expect the higher temps to occur across northern areas as clouds will advance from southwest to northeast on Saturday. Highs Saturday afternoon will range from the mid to upper 60s southeast to the upper 60s to mid 70s north. Lows Saturday night will be in the mid 40s to lower 50s. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Somewhat unsettled conditions will prevail for Sunday through at least Tuesday, as an upper level low develops near or off the northern Mid Atlantic coastline. Upper level energy and associated cold air aloft digging southward on Sunday will promote instability and some lift, and allow for scattered showers and isolated thunderstorms, especially in the afternoon hours. There is some uncertainty as to exactly where the core of coldest air aloft and upper level energy traverses, with some model guidance suggesting west of the region, with others farther east. For now, have indicated chc POPS for the afternoon hours, for scattered showers/isolated thunderstorms. Relatively low wet bulb zero heights could promote hail formation in any taller convection. This upper level energy will eventually help carve out the aforementioned upper level low across the northern Mid Atlantic coastline for Mon-Tue. A surface wave associated with this upper level feature is expected to develop off the northern Mid Atlantic coast, and track northward later Monday into Tuesday. There remains uncertainty as to how far west this surface wave tracks, along with its associated steady rain shield. Even if the main surface low tracks well offshore, the aforementioned upper level feature should remain close enough to allow for at least scattered showers across the region during this time period, which is indicated with chance POPS. However, there remains a possibility that a steadier period of rain occurs if the surface wave tracks farther west sometime late Monday or Tuesday. This upper level low should finally start to weaken and shift northeast by Wednesday, although there could be just enough cold air remaining aloft to allow for isolated afternoon showers, especially across higher terrain. As for temperatures, they should initially average near or a bit below normal for late May, with daytime highs in the lower 70s for valley areas, and 60s across higher terrain for Sunday through Tuesday. However, if steadier rain occurs with a more westward surface low track, much cooler high temperatures could occur. Overnight lows should mainly be in the mid 40s to lower 50s. Warmer temperatures are possible by Wednesday, assuming the main upper level low lifts away and enough breaks of sunshine develop. Maximum temperatures should reach 75-80 in valleys, and upper 60s to lower 70s across higher elevations. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... A closed upper level and its associated cold pool is moving over the region today. Clouds initially developed across the higher terrain. Scattered showers are occurring across the southern Adirondacks...Lake George Saratoga region and southern Vermont southern across the Berkshires. Chances for showers will persist through much of the afternoon as the cold pool moves overhead with the daytime heating. To address showers in TAFs have a tempo group in KGFL with VCSH in KALB and KPSF. No mention at KPOU. Cloud cover will decrease this evening as upper low moves off to the east tonight and ridging begins to build in at the surface and aloft. Do have a mention of MVFR fog in KGFL and KPSF for the overnight. Any fog will burn off quickly after sunrise. Ridging will continue build in at the surface and aloft Friday. Outlook... Friday Night: No Operational Impact. NO SIG WX. Saturday: Low Operational Impact. Slight Chance of SHRA. Saturday Night: Low Operational Impact. Slight Chance of SHRA. Sunday: Moderate Operational Impact. Scattered SHRA...TSRA. Sunday Night: Low Operational Impact. Isolated SHRA. Monday: Low Operational Impact. Isolated SHRA. Monday Night: Low Operational Impact. Isolated SHRA. Tuesday: Moderate Operational Impact. Scattered SHRA. && .FIRE WEATHER... An approaching upper level disturbance will allow for increasing clouds with a chance for some showers and possibly a thunderstorm today with seasonable temperatures. Although warmer temperatures with plenty of sunshine is expected on Friday, there will be chance for showers over the weekend. Relative humidity values will drop to 35 to 55 percent this afternoon...recover to 75 to 95 percent tonight...and drop to 30 to 50 percent on Friday. Winds will be northwest at 5 to 10 mph today and tonight and northwest around 5 mph on Friday. && .HYDROLOGY... There will be the chance for showers and a few thunderstorms mainly this afternoon. QPF amounts will generally be less than a quarter of an inch. Dry weather is expected on Friday with more unsettled weather over the weekend with up to another quarter of an inch of rain expected. Overall, this rainfall will have little impact on area rivers and streams. Most river levels will remain fairly steady through the weekend. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Frugis/11 NEAR TERM...IAA/11/JPV SHORT TERM...11 LONG TERM...KL AVIATION...IAA FIRE WEATHER...11 HYDROLOGY...Frugis/11
Area Forecast Discussion National Weather Service New York NY 127 PM EDT THU MAY 19 2016 .SYNOPSIS... A weak surface trough tracks across the area today...with high pressure regaining control to end the week. An unsettled weather pattern sets up this weekend and remains into early next week. High pressure builds in for Wednesday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Some updates for the near term forecast - have removed enhanced thunder and generally lowered pops. Upper low over near Ogdensburg as of 16Z as it tracks to northern Maine by this evening. Associated left exit region of upper level 100+ KT jet streak shift continues to shift east. Subsidence seen on observed ACARS profiles just above 700 mb. Latest RAP and Hrrr have this captured. The subsidence weakens late this afternoon to the north as backing winds above 700 hPa provides thermal wind cold advection. While WBZ heights are between 6-7k ft, believe hail threat is confined to perhaps some graupel as CAPE is only 100 to perhaps 200 J/kg. The inverted "V" sounding supports the potential for gusty winds with the showers and possible tstm. DCAPE`s in the latest HRRR are 300-600 J/kg. perhaps a gust to 35 KTs? Highs near normal levels in the upper 60s to lower 70s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Upper level low tracks through the canadian maritimes tonight and fri as ridging builds in from the west. Any showers / clouds dissipate with lose of daytime heating. Dry and seasonable weather is then expected through the day Friday with high pres building from the great lakes region to the mid atlantic coast. Expect sunny skies on Friday with highs in the lower to mid 70s. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Friday night high pressure over the region will be weakening in response to a combination of a northern stream eastern trough moving into eastern Canada and the northeastern United States and a southern stream shortwave moving of the central plains and into the mid atlantic region. Meanwhile a surface low deepens along the southeastern coast and track south and east of the region Saturday into Sunday. Current guidance is keeping the surface low farther to the south and east as the upper trough digs along the eastern United States. So have lowered the chances for rainfall for the upcoming weekend. An Omega block sets up Saturday night, with the eastern trough remaining, a ridge building through the central states and into south central Canada, and another deep trough along the west coast. A cutoff low eventually develops, Monday into Monday night, along the coast and over the western Atlantic. Unsettled weather continues into at least Tuesday as the upper low meanders along the east coast. There remains a lot of uncertainty as to when the low starts to moves and where the low will go. So for now have mainly slight chance to low chance pops Sunday into Wednesday. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... High pressure builds into the region this afternoon as an upper level disturbance passes north of the region. VFR through the TAF period. Expect a broken ceilings around 5000-6000ft this afternoon. Isolated-scattered showers are possible this afternoon, but confidence in occurrence at any given location remains too low to reflect in TAFs at this time. The best chance of any showers will be north of NYC. Sea breezes at coastal terminals will occur through this afternoon becoming light and variable tonight. The exception is at KSWF where no sea breeze is expected, but NW flow under 10 kt should develop. On Friday...mainly nw flow is expected around 10-15 KTs. A coastal sea breeze is possible kJFK and KISP due to light gradient. NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: No unscheduled amendments are expected. KLGA TAF Comments: No unscheduled amendments are expected. KEWR TAF Comments: No unscheduled amendments are expected. KTEB TAF Comments: No unscheduled amendments are expected. KHPN TAF Comments: No unscheduled amendments are expected. KISP TAF Comments: No unscheduled amendments are expected. .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY: .18z Friday and Friday night...VFR. .Saturday-Sunday...MVFR or lower possible in rain...depending on exact track of coastal low. Best chance is at NYC and Long Island Terminals. NE-N winds G20-30kt possible. .Sunday Night-Tuesday...Most likely VFR. However, cannot rule out a few showers with possible MVFR conditions. && .MARINE... Sub-advsy conds are forecast through Fri with the area in a weak pres gradient regime. Winds from Friday night into Monday will remain below small craft levels as a weak pressure gradient force remains across the forecast waters. Ocean seas may build to small craft levels Saturday night and remain at small craft levels into Sunday night as a low passes south and east of the ocean waters. && .HYDROLOGY... no appreciable rain is expected through friday. Saturday into Saturday night around a quarter of an inch of rainfall is possible. Rainfall is possible Sunday through Wednesday with no hydrologic impacts expected. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS... NEAR TERM...Tongue SHORT TERM... LONG TERM... AVIATION...IRD MARINE...Tongue HYDROLOGY...