Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 06/20/16

Area Forecast Discussion
National Weather Service Denver/Boulder CO
820 PM MDT SUN JUN 19 2016

.UPDATE...
Issued at 813 PM MDT Sun Jun 19 2016

Drier air moving into northern Colorado behind a cold front.
Late afternoon convection along the dry line was very marginal and
moisture appears to have mixed out. That area will likely stay
capped now. One strong storm in the sweet spot over the Palmer
Divide with enough heat and moisture at the end of the day. Some
potential for this to work its way southeastward with good moist
inflow, however the air it`s moving into is potentially cooler so
I don`t expect this to last very long.

Made some adjustments to the forecast for later tonight and
tomorrow. Incoming air is cooler. NAM looks to overdue the
moisture as the air in eastern Wyoming has a bit more moisture
than what is coming in now, but the richer moisture is further
east and may not make it all the way to the Front Range. Some
potential for some shallow stratus for a while in the morning, but
this may stay further east. With the cooling I backed off on POPs
for late tonight and Monday morning though there is still a slim
chance for lift from aloft to produce light showers out on the
northeast plains. Best chance is probably stuff moving off the
more unstable mountains in the late afternoon so I shaded the
forecast toward this idea.

&&

.SHORT TERM...(This evening through Monday)
Issued at 301 PM MDT Sun Jun 19 2016

Satellite showing cold front entering portions of the northern
counties of CO bringing cooler temperatures and increased
moisture behind it. This moisture will move onto the plains
through the afternoon and evening as will increased NE winds.
Short term models indicating the formation of a convergence line
over the SE counties of Douglas...lincoln and over the eastern
portions of the CWA this evening. CAPE values are strong at 2000+
j/kg with deep layer shear in the 30s. This could bring some
strong to possibly severe storms later this evening. Look for a
more mild evening with clouds moving in behind the front that will
maintain overnight temperatures in the low 60s.

For Monday...temperatures will drop back to near average with
highs in the mid 80s. Low level stratus will move in during the
morning with a strong mid level inversion around 700 mb. This
inversion will help to cap convection on the plains for tomorrow
afternoon. In the mountains model soundings show 2000+ CAPE
values that could bring storms in the afternoon. Will increase
pops for the higher elevations and onto the Palmer Divide for tomorrow
afternoon. With the cap confidence is low that the plains will be
able to have any convection...however moisture levels are high
with the possibility of stratiform rain over portions of the
plains by tomorrow afternoon.

.LONG TERM...(Monday night through Sunday)
Issued at 301 PM MDT Sun Jun 19 2016

Models feature a substantial upper level high centered over
southwestern Colorado Monday night into to Tuesday night. The
upper ridge weakens a tad by Wednesday and Wednesday night, but it
is still omnipresent concerning the CWA`s weather. The models keep
southwesterly 30-40 knot winds aloft for the CWA through Wednesday
night. The QG Omega fields show benign synoptic scale energy for
the forecast area through the periods. The boundary layer flow
looks to adhere to normal diurnal trends Monday night into
Wednesday morning. Models have a decent surge and northeasterly
upslope move into the plains and foothills by 12z Wednesday
morning. This continues into Wednesday evening, with drainage
after midnight. Concerning moisture, there is some Monday evening,
less late day Tuesday. Wednesday afternoon and night, models have
quite a bit of moisture, especially in the upper levels. Boundary
layer dew points are in the lower 40s F to lower 60s F range late
day Monday. By Tuesday, they are lower, with mid 30s F west to
lower 50s F east. On Wednesday, they are progged in the lower 30s
F west to upper 40s F east. Precipitable water values are in the
0.60 to 1.30 inch range Monday evening, then 0.40 to 1.00 inch
late day Tuesday and late day Wednesday. The CAPE values are well
over 2000 J/kg Monday evening, with maybe 1000 J/kg, mostly in the
mountains for late day Tuesday. The CAPE is pretty high in the
mountains late day Wednesday, with way less over the plains.
Soundings over the plains show a substantial stable layer Monday
evening and again late day Wednesday, both time behind the passage
of a new cooler airmass. The QPF fields shows minimal measurable
rainfall over the mountians Monday evening and again late day
Wednesday. For pops, will go with "chance"s over the mountians and
foothills Monday evening and late day Wednesday, with mostly 0%s
for the stable plains. For late day Tuesday 0-20%s will do, with
best chances in the mountians. Concerning temperatures, Tuesday
highs are up 5-10 C from Monday`s. Tuesday`s highs will be close
to this afternoon`s. On Wednesday, readings cool off 5-10 C from
Tuesday`s. For the later days, Thursday through Sunday, the models
flatten the upper ridge somewhat with the center shifting to our
southeast from time to time. There is a bit of moisture around,
more so on the ECMWF. Temperatures look to remain above normal.
The best pops will be "slight chance"s mainly in the mountians.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 813 PM MDT Sun Jun 19 2016

There is a chance of MVFR ceilings Monday morning between 12z and
18z, otherwise VFR conditions are expected. Isolated thunderstorms
are expected Monday afternoon after 21z.

&&

.BOU Watches/Warnings/Advisories...
None.
&&

$$

UPDATE...Gimmestad
SHORT TERM...Bowen
LONG TERM...RJK
AVIATION...Gimmestad



Area Forecast Discussion...CORRECTED National Weather Service Denver/Boulder CO 345 PM MDT SUN JUN 19 2016 .SHORT TERM...(This evening through Monday) Issued at 301 PM MDT Sun Jun 19 2016 Satellite showing cold front entering portions of the northern counties of CO bringing cooler temperatures and increased moisture behind it. This moisture will move onto the plains through the afternoon and evening as will increased NE winds. Short term models indicating the formation of a convergence line over the SE counties of Douglas...lincoln and over the eastern portions of the CWA this evening. CAPE values are strong at 2000+ j/kg with deep layer shear in the 30s. This could bring some strong to possibly severe storms later this evening. Look for a more mild evening with clouds moving in behind the front that will maintain overnight temperatures in the low 60s. For Monday...temperatures will drop back to near average with highs in the mid 80s. Low level stratus will move in during the morning with a strong mid level inversion around 700 mb. This inversion will help to cap convection on the plains for tomorrow afternoon. In the mountains model soundings show 2000+ CAPE values that could bring storms in the afternoon. Will increase pops for the higher elevations and onto the Palmer Divide for tomorrow afternoon. With the cap confidence is low that the plains will be able to have any convection...however moisture levels are high with the possibility of stratiform rain over portions of the plains by tomorrow afternoon. .LONG TERM...(Monday night through Sunday) Issued at 301 PM MDT Sun Jun 19 2016 Models feature a substantial upper level high centered over southwestern Colorado Monday night into to Tuesday night. The upper ridge weakens a tad by Wednesday and Wednesday night, but it is still omnipresent concerning the CWA`s weather. The models keep southwesterly 30-40 knot winds aloft for the CWA through Wednesday night. The QG Omega fields show benign synoptic scale energy for the forecast area through the periods. The boundary layer flow looks to adhere to normal diurnal trends Monday night into Wednesday morning. Models have a decent surge and northeasterly upslope move into the plains and foothills by 12z Wednesday morning. This continues into Wednesday evening, with drainage after midnight. Concerning moisture, there is some Monday evening, less late day Tuesday. Wednesday afternoon and night, models have quite a bit of moisture, especially in the upper levels. Boundary layer dew points are in the lower 40s F to lower 60s F range late day Monday. By Tuesday, they are lower, with mid 30s F west to lower 50s F east. On Wednesday, they are progged in the lower 30s F west to upper 40s F east. Precipitable water values are in the 0.60 to 1.30 inch range Monday evening, then 0.40 to 1.00 inch late day Tuesday and late day Wednesday. The CAPE values are well over 2000 J/kg Monday evening, with maybe 1000 J/kg, mostly in the mountains for late day Tuesday. The CAPE is pretty high in the mountains late day Wednesday, with way less over the plains. Soundings over the plains show a substantial stable layer Monday evening and again late day Wednesday, both time behind the passage of a new cooler airmass. The QPF fields shows minimal measurable rainfall over the mountians Monday evening and again late day Wednesday. For pops, will go with "chance"s over the mountians and foothills Monday evening and late day Wednesday, with mostly 0%s for the stable plains. For late day Tuesday 0-20%s will do, with best chances in the mountians. Concerning temperatures, Tuesday highs are up 5-10 C from Monday`s. Tuesday`s highs will be close to this afternoon`s. On Wednesday, readings cool off 5-10 C from Tuesday`s. For the later days, Thursday through Sunday, the models flatten the upper ridge somewhat with the center shifting to our southeast from time to time. There is a bit of moisture around, more so on the ECMWF. Temperatures look to remain above normal. The best pops will be "slight chance"s mainly in the mountians. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 301 PM MDT Sun Jun 19 2016 Conditions will be VFR through 12z on Monday with possible MVFR conditions through the morning and into the afternoon. A lowered stratus deck around 015 will be possible with increased moisture from cold frontal passage. For tonight...winds will increase from the NE behind the cold front before switching to the NNW by 06z tonight. There is a slight chance of rain over area airports by tomorrow afternoon but confidence is low for convection with mid level warming providing a strong cap over the plains. && .BOU Watches/Warnings/Advisories... None. && $$ SHORT TERM...Bowen LONG TERM...RJK AVIATION...Bowen
  [top] Area Forecast Discussion National Weather Service Grand Junction CO 330 PM MDT SUN JUN 19 2016 .SHORT TERM...(This evening through Monday night) Issued at 330 PM MDT Sun Jun 19 2016 High pressure remained stretched across the Desert Southwest to the central High Plains today. Some mid and high clouds showed up overnight extending southwest to northeast across northeast Utah and northwest Colorado. Models indicated roughly 0.5 of an inch precipitable water corresponding to the cloud field. This high based moisture appeared insufficient to fuel even isolated storms over the higher terrain late this afternoon and early evening. As temperatures fall this evening, convective clouds will dissipate leaving clear skies over the region. Strong radiational cooling will provide quick relief from unseasonable afternoon heat. Another hot day in store Monday as high pressure persists over the region. Model guidance continued to forecast record or near record heat with a number of valley locations expected to reach 100 degrees or more. Marginal flow beneath the ridge suggests light terrain driven winds. Meanwhile, relatively moist air over the eastern Colorado plains is drawn westward toward the surface heat low centered over northeast Arizona. This will result in isolated to widely scattered thunderstorms along the Continental Divide during the afternoon. This high based moist convection will generate little measurable rainfall and strong outflow winds. Expect diurnal cooling to bring this activity to a halt around sunset with clearing during the remainder of the night. Overnight lows for early Tuesday morning will be just a degree or two milder than last night on average. .LONG TERM...(Tuesday through Sunday) Issued at 330 PM MDT Sun Jun 19 2016 Near record heat will continue Tuesday as high pressure remains over the area. Meanwhile, models indicated a passing short-wave trough to the north will flatten the ridge while driving a cool front across the northern zones late in the day. The front will not arrive early enough to bring cooling, but will enhance gradient winds north of the I-70 corridor. Elsewhere, moisture infiltrating the ridge from the east and south will fuel scattered afternoon/evening showers and thunderstorms, mainly over higher terrain. Cooler temperatures are in store across the north from Wednesday onward as the front stalls along the Roan Plateau and the Flat Tops, while unseasonably warm temperatures persist along and south of the I-70 corridor. A recycling of moisture beneath the flat ridge is expected to fuel scattered showers and thunderstorms each afternoon and evening during the remainder of the week. GFS and EC were divided on whether similar conditions will continue into the weekend. The dry GFS suggested that another passing short-wave trough will spread drier air over the forecast area in its wake ending afternoon/evening moist convection. The ECMWF indicated less influence from the short-wave and thus continued activity during the hotter part of the day into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 330 PM MDT Sun Jun 19 2016 Expect VFR conditions to persist through the next 24 hours. Near record warmth will negatively impact AIRCRAFT performance, especially at the higher elevation airports across the region. Winds will remain relatively light and terrain driven. Widely scattered thunderstorms are expected to develop along the Continental Divide during the afternoon Monday producing strong and unpredictable outflow winds. && .FIRE WEATHER... Issued at 330 PM MDT Sun Jun 19 2016 A disturbance passing to the north of the forecast area on Tuesday will bing a cool front to the northern fire weather zones during the afternoon. The cool front will not arrive in time to bring down temperatures, but will generate gusty west winds ahead of it which, when combined with low relative humidity, may result in critical fire weather conditions. Therefore, a watch has been issued for the lower elevation fire weather zones of northwest Colorado from noon through 8 PM MDT on Tuesday. && .HYDROLOGY... Issued at 330 PM MDT Sun Jun 19 2016 Above normal temperatures will continue for the next several days at least. These high temperatures will exacerbate the melting of the remaining high elevation snowpack. Meanwhile, releases from area dams and management of water diversions will likely add to flow in some rivers and streams. As a result, waterways across the area will continue to run high, fast, and cold through the coming week. Stay advised of the latest river forecasts by visiting our website at weather.gov/gjt. && .GJT Watches/Warnings/Advisories... CO...Fire Weather Watch from Tuesday afternoon through Tuesday evening for COZ200-202. UT...None. && $$ SHORT TERM...NL LONG TERM...NL AVIATION...NL FIRE WEATHER...NL HYDROLOGY...TGJT Area Forecast Discussion National Weather Service Denver/Boulder CO 350 AM MDT MON JUN 20 2016 .SHORT TERM...(Today and tonight) Issued at 350 AM MDT Mon Jun 20 2016 Surface high pressure moving east across the northern part of the country will push a cold front through the area early this morning. Currently the front is over southeast Wyoming and western Nebraska. This will increase low level moisture, cool temperatures, and bring northeast winds today. Huge difference between the short term models this morning regarding highs for today. The 06z NAMNest shows a high of 73 degrees for Denver while the 07z RAP has a high of 93. So the confidence in the temperature forecast will be low for today. A lot will depend how much cloud cover develops this morning and how long it sticks around. Will go with temperatures close to the middle of the extremes with highs in the lower to mid 80s. For the eastern plains where fewer clouds are expected, will go with highs in the upper 80s to lower 90s. As far as convection goes, with the cooler air at the surface and warm air aloft, expect most of the plains to be capped from convection today. Many of the models show storms forming over Park county, the Palmer Divide and the Southern Foothills early this afternoon. Increased pops into the 30-50 percent range. Elsewhere, will keep pops low, 10-20 percent. Surface based CAPE values will be 1000-2000 J/kg today. Northeast low level winds with southwest winds aloft will result in somewhat decent shear today. So some of the storms that form could become severe with large hail the main threat. Damaging winds will also be possible. .LONG TERM...(Tuesday through Sunday) Issued at 350 AM MDT Mon Jun 20 2016 Relief from the heat will be very brief as a strong ridge of high pressure will allow for temperatures to bounce back into the mid and upper 90s on Tuesday. 700 MB TEMPERATURES IN THE AFTN WILL BE AROUND 18C...which will translate to readings around 97. There will be some CAPE in the 500-600 j/kg around with some residual mid level moisture. The best chc of any tstms will be in and near the higher terrain in the late aftn/evening period. Fire danger will be high over Jackson and northwest parts of Larimer County so day shift may want to look into a Fire Weather Watch for this area. Tuesday night...an upper level trough passing across the northern rockies will push a weak frontal boundary through the cwa. As a result... high temperatures on Wednesday will not be as hot but still above normal. In addition...the ridge aloft will get pushed a little further south which should allow for a better chance of tstms in the aftn/evening. With the upper ridge more to the south and east of CO on Thursday...there will be a little better connection to some subtropical moisture which will result in a better chance of aftn and evening tstms...especially in the mountains. The models also hint at a weak upper level disturbance possibly moving across eastern CO on Thursday as well. The ridge will remain south of CO on Friday with a little stronger westerly flow aloft as a stronger looking trough moves across the northern Rockies Friday night into Saturday. This will result in slightly cooler temperatures over the weekend. Timing of this system will impact the potential thunderstorm chances on Saturday. If it moves through too soon...then subsidence behind the trough will negate the chance for some tstms in the aftn. By Sunday...the flow aloft will be northwesterly over the cwa with the ridge recentering itself near the Four Corners Region. Subtropical moisture gets pinched off by that time which will lessen the chance of aftn/evening tstms for Sunday as well. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 350 AM MDT Mon Jun 20 2016 Low clouds over southeast Wyoming and western Nebraska are expected to spread south during the early morning hours behind a weak cold front. These low clouds are expected to affect the Denver area around 13z. Ceilings of 1000 to 2000 feet are expected beneath these low clouds. These low clouds may linger through around 18z. Winds behind the front will be northeasterly. Just a slight chance for a thunderstorm at the Denver airports today, not enough of a chance to mention in the TAFs. There will be a better chance for thunderstorms over the higher terrain to the south and southwest of Denver. && .BOU Watches/Warnings/Advisories... None. && $$ SHORT TERM...Meier LONG TERM...Cooper AVIATION...Meier
  [top] Area Forecast Discussion National Weather Service Pueblo CO 349 AM MDT MON JUN 20 2016 .SHORT TERM...(Today and tonight) Issued at 348 AM MDT Mon Jun 20 2016 Currently...quiet conditions prevail across southern Colorado early this morning. Temperatures are in the mid 60s to lower 70s with a few degrees of cooling expected through sunrise. Today...upper level high pressure will remain centered near the Four Corners. Moisture embedded in the upper level high along with an upper level wave rotating within weak upper level flow will set the stage for afternoon isolated to scattered showers and thunderstorms mainly across and near the higher terrain. Low level moisture convergence along a stalled boundary near the Palmer Divide will likely lead to scattered thunderstorms across northern Teller and El Paso Counties by the late afternoon hours. A few stronger storms along the boundary in El Paso County cannot be ruled out as CAPE values will run between 2000-2500 J/KG with marginal 0-6 km bulk shear values between 20-25 knots. Afternoon high temperatures will remain hot, with readings close to the century mark across the Arkansas River Valley. Tonight...showers and thunderstorms are expected to end by midnight with the loss of solar heating. Overnight temperatures will dip into mid-60s across the plains and into the low to mid-50s across high valley areas. Lukinbeal/Mozley .LONG TERM...(Tuesday through Sunday) Issued at 348 AM MDT Mon Jun 20 2016 Tuesday...For the first full day of summer, the center of the latitudinal upper high is forecast by models to be south of the CWA, so relatively weak west to southwest upper flow will prevail. Residual moisture and a shortwave moving along the northern periphery of the upper ridge will spark isolated to scattered storms during the afternoon and evening. The best coverage is expected to be across and near the higher terrain. Lee trough forecast to be across the plains will help to mix out the atmosphere, and with warm mid level temperatures, surface highs will reach the 90s to around 101. Highs will be in the 70s and 80s across the higher terrain and 50s to lower 60s mountains. Wednesday-Thursday...An increase in westerly flow is forecast by models across Colorado as the upper ridge migrates farther south, pushed by shortwaves rippling through the flow north of the state. One shortwave moves through the flow, sending another weak front through eastern Colorado Wednesday. This will lower high temperatures and bring bring better coverage of afternoon and evening showers and storms across the higher terrain, and spreading farther east onto the plains. Broad scale lift with upper impulse moving through on Thursday suggests another batch of isolated to scattered afternoon and evening showers and storms, with temperatures at and slightly above seasonal averages. Friday-Sunday...There will be chances for afternoon and evening showers and thunderstorms, especially Friday and Saturday, with a stronger disturbance moving across the northern US. This will send another shot of cooler air into the plains Friday night and Saturday. It looks like there will be a lesser chance for showers and storms on Sunday with the upper ridge building again. Temperatures through the period will be slightly above seasonal averages. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday) Issued at 348 AM MDT Mon Jun 20 2016 VFR conditions are expected to prevail at all three terminals through the next 24 hours. Southeast winds will increase with gusts to near 20 kts at KCOS and KPUB for this afternoon. Isolated showers and thunderstorms are possible late this afternoon and evening at KCOS. If storms can move over the terminal, they will bring reduced CIGS and VIS along with the possibility of small hail. Mozley && .PUB Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...MOZLEY LONG TERM...TM AVIATION...MOZLEY
  [top] Area Forecast Discussion National Weather Service Grand Junction CO 328 AM MDT MON JUN 20 2016 .SHORT TERM...(Today through Tuesday) Issued at 302 AM MDT Mon Jun 20 2016 The first day of summer will not disappoint. In fact, it may be a record breaker for some areas. High pressure remains overhead as some high clouds move overhead from time to time while some afternoon cumulus form over higher terrain. Warm air advection continues aloft and will be reflected at the surface today with temperatures continuing their upward climb. Temperatures in the low to mid 100s will be common over southeastern Utah while most Colorado valleys will flirt with triple digits except the Grand Valley which looks to hit the low 100s this afternoon. While PWATs remain near .5 inches or so, models continue to depict some high- based afternoon and evening convection along the Divide and also the San Juans. This convection will die down quickly after sunset. Tuesday, expect more of the same. Little change to high temperatures with another possible record breaking day in store. Higher PWAT values located down south will start to advect northward Tuesday with values reaching .7 inches or so. Showers and storms will increase in coverage forming over higher terrain in the CWA and will be high- based with the main concern being some gusty surface winds under and near any showers or storms that collapse. .LONG TERM...(Wednesday through Sunday) Issued at 330 PM MDT Sun Jun 19 2016 Cooler temperatures are in store across the north from Wednesday onward as the front stalls along the Roan Plateau and the Flat Tops, while unseasonably warm temperatures persist along and south of the I-70 corridor. A recycling of moisture beneath the flat ridge is expected to fuel scattered showers and thunderstorms each afternoon and evening during the remainder of the week. GFS and EC were divided on whether similar conditions will continue into the weekend. The dry GFS suggested that another passing short-wave trough will spread drier air over the forecast area in its wake ending afternoon/evening moist convection. The ECMWF indicated less influence from the short-wave and thus continued activity during the hotter part of the day into the weekend. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) Issued at 302 AM MDT Mon Jun 20 2016 Very hot temperatures will cause density altitude to spike this afternoon. Because of this, engine characteristics will be affected as performance suffers. A few showers and storms will fire over the Continental Divide and San Juans and will be high based so expect some gusty winds from these features. At this time, do not anticipate any problems at TAF sites. && .FIRE WEATHER... Issued at 330 PM MDT Sun Jun 19 2016 A disturbance passing to the north of the forecast area on Tuesday will bring a cool front to the northern fire weather zones during the afternoon. The cool front will not arrive in time to bring down temperatures, but will generate gusty west winds ahead of it which, when combined with low relative humidity, may result in critical fire weather conditions. Therefore, a watch has been issued for the lower elevation fire weather zones of northwest Colorado from noon through 8 PM MDT on Tuesday. && .HYDROLOGY... Issued at 330 PM MDT Sun Jun 19 2016 Above normal temperatures will continue for the next several days at least. These high temperatures will exacerbate the melting of the remaining high elevation snowpack. Meanwhile, releases from area dams and management of water diversions will likely add to flow in some rivers and streams. As a result, waterways across the area will continue to run high, fast, and cold through the coming week. Stay advised of the latest river forecasts by visiting our website at weather.gov/gjt. && .GJT Watches/Warnings/Advisories... CO...Fire Weather Watch from Tuesday afternoon through Tuesday evening for COZ200-202. UT...None. && $$ SHORT TERM...TGR LONG TERM...NL AVIATION...TGR FIRE WEATHER...NL HYDROLOGY...TGJT
Area Forecast Discussion National Weather Service Grand Junction CO 1127 PM MDT SUN JUN 19 2016 .SHORT TERM...(This evening through Monday night) Issued at 330 PM MDT Sun Jun 19 2016 High pressure remained stretched across the Desert Southwest to the central High Plains today. Some mid and high clouds showed up overnight extending southwest to northeast across northeast Utah and northwest Colorado. Models indicated roughly 0.5 of an inch precipitable water corresponding to the cloud field. This high based moisture appeared insufficient to fuel even isolated storms over the higher terrain late this afternoon and early evening. As temperatures fall this evening, convective clouds will dissipate leaving clear skies over the region. Strong radiational cooling will provide quick relief from unseasonable afternoon heat. Another hot day in store Monday as high pressure persists over the region. Model guidance continued to forecast record or near record heat with a number of valley locations expected to reach 100 degrees or more. Marginal flow beneath the ridge suggests light terrain driven winds. Meanwhile, relatively moist air over the eastern Colorado plains is drawn westward toward the surface heat low centered over northeast Arizona. This will result in isolated to widely scattered thunderstorms along the Continental Divide during the afternoon. This high based moist convection will generate little measurable rainfall and strong outflow winds. Expect diurnal cooling to bring this activity to a halt around sunset with clearing during the remainder of the night. Overnight lows for early Tuesday morning will be just a degree or two milder than last night on average. .LONG TERM...(Tuesday through Sunday) Issued at 330 PM MDT Sun Jun 19 2016 Near record heat will continue Tuesday as high pressure remains over the area. Meanwhile, models indicated a passing short-wave trough to the north will flatten the ridge while driving a cool front across the northern zones late in the day. The front will not arrive early enough to bring cooling, but will enhance gradient winds north of the I-70 corridor. Elsewhere, moisture infiltrating the ridge from the east and south will fuel scattered afternoon/evening showers and thunderstorms, mainly over higher terrain. Cooler temperatures are in store across the north from Wednesday onward as the front stalls along the Roan Plateau and the Flat Tops, while unseasonably warm temperatures persist along and south of the I-70 corridor. A recycling of moisture beneath the flat ridge is expected to fuel scattered showers and thunderstorms each afternoon and evening during the remainder of the week. GFS and EC were divided on whether similar conditions will continue into the weekend. The dry GFS suggested that another passing short-wave trough will spread drier air over the forecast area in its wake ending afternoon/evening moist convection. The ECMWF indicated less influence from the short-wave and thus continued activity during the hotter part of the day into the weekend. && .AVIATION...(For the 06Z TAFS through 06Z Monday evening) Issued at 1125 PM MDT Sun Jun 19 2016 Expect VFR conditions to persist through the next 24 hours. Near record warmth will negatively impact AIRCRAFT performance, especially at the higher elevation airports across the region. Winds will remain relatively light and terrain driven. Isolated thunderstorms are expected to develop along the Continental Divide during the afternoon producing strong erratic outflow winds. && .FIRE WEATHER... Issued at 330 PM MDT Sun Jun 19 2016 A disturbance passing to the north of the forecast area on Tuesday will bing a cool front to the northern fire weather zones during the afternoon. The cool front will not arrive in time to bring down temperatures, but will generate gusty west winds ahead of it which, when combined with low relative humidity, may result in critical fire weather conditions. Therefore, a watch has been issued for the lower elevation fire weather zones of northwest Colorado from noon through 8 PM MDT on Tuesday. && .HYDROLOGY... Issued at 330 PM MDT Sun Jun 19 2016 Above normal temperatures will continue for the next several days at least. These high temperatures will exacerbate the melting of the remaining high elevation snowpack. Meanwhile, releases from area dams and management of water diversions will likely add to flow in some rivers and streams. As a result, waterways across the area will continue to run high, fast, and cold through the coming week. Stay advised of the latest river forecasts by visiting our website at weather.gov/gjt. && .GJT Watches/Warnings/Advisories... CO...Fire Weather Watch from Tuesday afternoon through Tuesday evening for COZ200-202. UT...None. && $$ SHORT TERM...NL LONG TERM...NL AVIATION...TGJT FIRE WEATHER...NL HYDROLOGY...TGJT Area Forecast Discussion National Weather Service Denver/Boulder CO 350 AM MDT MON JUN 20 2016 .SHORT TERM...(Today and tonight) Issued at 350 AM MDT Mon Jun 20 2016 Surface high pressure moving east across the northern part of the country will push a cold front through the area early this morning. Currently the front is over southeast Wyoming and western Nebraska. This will increase low level moisture, cool temperatures, and bring northeast winds today. Huge difference between the short term models this morning regarding highs for today. The 06z NAMNest shows a high of 73 degrees for Denver while the 07z RAP has a high of 93. So the confidence in the temperature forecast will be low for today. A lot will depend how much cloud cover develops this morning and how long it sticks around. Will go with temperatures close to the middle of the extremes with highs in the lower to mid 80s. For the eastern plains where fewer clouds are expected, will go with highs in the upper 80s to lower 90s. As far as convection goes, with the cooler air at the surface and warm air aloft, expect most of the plains to be capped from convection today. Many of the models show storms forming over Park county, the Palmer Divide and the Southern Foothills early this afternoon. Increased pops into the 30-50 percent range. Elsewhere, will keep pops low, 10-20 percent. Surface based CAPE values will be 1000-2000 J/kg today. Northeast low level winds with southwest winds aloft will result in somewhat decent shear today. So some of the storms that form could become severe with large hail the main threat. Damaging winds will also be possible. .LONG TERM...(Tuesday through Sunday) Issued at 350 AM MDT Mon Jun 20 2016 Relief from the heat will be very brief as a strong ridge of high pressure will allow for temperatures to bounce back into the mid and upper 90s on Tuesday. 700 MB TEMPERATURES IN THE AFTN WILL BE AROUND 18C...which will translate to readings around 97. There will be some CAPE in the 500-600 j/kg around with some residual mid level moisture. The best chc of any tstms will be in and near the higher terrain in the late aftn/evening period. Fire danger will be high over Jackson and northwest parts of Larimer County so day shift may want to look into a Fire Weather Watch for this area. Tuesday night...an upper level trough passing across the northern rockies will push a weak frontal boundary through the cwa. As a result... high temperatures on Wednesday will not be as hot but still above normal. In addition...the ridge aloft will get pushed a little further south which should allow for a better chance of tstms in the aftn/evening. With the upper ridge more to the south and east of CO on Thursday...there will be a little better connection to some subtropical moisture which will result in a better chance of aftn and evening tstms...especially in the mountains. The models also hint at a weak upper level disturbance possibly moving across eastern CO on Thursday as well. The ridge will remain south of CO on Friday with a little stronger westerly flow aloft as a stronger looking trough moves across the northern Rockies Friday night into Saturday. This will result in slightly cooler temperatures over the weekend. Timing of this system will impact the potential thunderstorm chances on Saturday. If it moves through too soon...then subsidence behind the trough will negate the chance for some tstms in the aftn. By Sunday...the flow aloft will be northwesterly over the cwa with the ridge recentering itself near the Four Corners Region. Subtropical moisture gets pinched off by that time which will lessen the chance of aftn/evening tstms for Sunday as well. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 350 AM MDT Mon Jun 20 2016 Low clouds over southeast Wyoming and western Nebraska are expected to spread south during the early morning hours behind a weak cold front. These low clouds are expected to affect the Denver area around 13z. Ceilings of 1000 to 2000 feet are expected beneath these low clouds. These low clouds may linger through around 18z. Winds behind the front will be northeasterly. Just a slight chance for a thunderstorm at the Denver airports today, not enough of a chance to mention in the TAFs. There will be a better chance for thunderstorms over the higher terrain to the south and southwest of Denver. && .BOU Watches/Warnings/Advisories... None. && $$ SHORT TERM...Meier LONG TERM...Cooper AVIATION...Meier
  [top] Area Forecast Discussion National Weather Service Pueblo CO 349 AM MDT MON JUN 20 2016 .SHORT TERM...(Today and tonight) Issued at 348 AM MDT Mon Jun 20 2016 Currently...quiet conditions prevail across southern Colorado early this morning. Temperatures are in the mid 60s to lower 70s with a few degrees of cooling expected through sunrise. Today...upper level high pressure will remain centered near the Four Corners. Moisture embedded in the upper level high along with an upper level wave rotating within weak upper level flow will set the stage for afternoon isolated to scattered showers and thunderstorms mainly across and near the higher terrain. Low level moisture convergence along a stalled boundary near the Palmer Divide will likely lead to scattered thunderstorms across northern Teller and El Paso Counties by the late afternoon hours. A few stronger storms along the boundary in El Paso County cannot be ruled out as CAPE values will run between 2000-2500 J/KG with marginal 0-6 km bulk shear values between 20-25 knots. Afternoon high temperatures will remain hot, with readings close to the century mark across the Arkansas River Valley. Tonight...showers and thunderstorms are expected to end by midnight with the loss of solar heating. Overnight temperatures will dip into mid-60s across the plains and into the low to mid-50s across high valley areas. Lukinbeal/Mozley .LONG TERM...(Tuesday through Sunday) Issued at 348 AM MDT Mon Jun 20 2016 Tuesday...For the first full day of summer, the center of the latitudinal upper high is forecast by models to be south of the CWA, so relatively weak west to southwest upper flow will prevail. Residual moisture and a shortwave moving along the northern periphery of the upper ridge will spark isolated to scattered storms during the afternoon and evening. The best coverage is expected to be across and near the higher terrain. Lee trough forecast to be across the plains will help to mix out the atmosphere, and with warm mid level temperatures, surface highs will reach the 90s to around 101. Highs will be in the 70s and 80s across the higher terrain and 50s to lower 60s mountains. Wednesday-Thursday...An increase in westerly flow is forecast by models across Colorado as the upper ridge migrates farther south, pushed by shortwaves rippling through the flow north of the state. One shortwave moves through the flow, sending another weak front through eastern Colorado Wednesday. This will lower high temperatures and bring bring better coverage of afternoon and evening showers and storms across the higher terrain, and spreading farther east onto the plains. Broad scale lift with upper impulse moving through on Thursday suggests another batch of isolated to scattered afternoon and evening showers and storms, with temperatures at and slightly above seasonal averages. Friday-Sunday...There will be chances for afternoon and evening showers and thunderstorms, especially Friday and Saturday, with a stronger disturbance moving across the northern US. This will send another shot of cooler air into the plains Friday night and Saturday. It looks like there will be a lesser chance for showers and storms on Sunday with the upper ridge building again. Temperatures through the period will be slightly above seasonal averages. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday) Issued at 348 AM MDT Mon Jun 20 2016 VFR conditions are expected to prevail at all three terminals through the next 24 hours. Southeast winds will increase with gusts to near 20 kts at KCOS and KPUB for this afternoon. Isolated showers and thunderstorms are possible late this afternoon and evening at KCOS. If storms can move over the terminal, they will bring reduced CIGS and VIS along with the possibility of small hail. Mozley && .PUB Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...MOZLEY LONG TERM...TM AVIATION...MOZLEY
  [top] Area Forecast Discussion National Weather Service Grand Junction CO 328 AM MDT MON JUN 20 2016 .SHORT TERM...(Today through Tuesday) Issued at 302 AM MDT Mon Jun 20 2016 The first day of summer will not disappoint. In fact, it may be a record breaker for some areas. High pressure remains overhead as some high clouds move overhead from time to time while some afternoon cumulus form over higher terrain. Warm air advection continues aloft and will be reflected at the surface today with temperatures continuing their upward climb. Temperatures in the low to mid 100s will be common over southeastern Utah while most Colorado valleys will flirt with triple digits except the Grand Valley which looks to hit the low 100s this afternoon. While PWATs remain near .5 inches or so, models continue to depict some high- based afternoon and evening convection along the Divide and also the San Juans. This convection will die down quickly after sunset. Tuesday, expect more of the same. Little change to high temperatures with another possible record breaking day in store. Higher PWAT values located down south will start to advect northward Tuesday with values reaching .7 inches or so. Showers and storms will increase in coverage forming over higher terrain in the CWA and will be high- based with the main concern being some gusty surface winds under and near any showers or storms that collapse. .LONG TERM...(Wednesday through Sunday) Issued at 330 PM MDT Sun Jun 19 2016 Cooler temperatures are in store across the north from Wednesday onward as the front stalls along the Roan Plateau and the Flat Tops, while unseasonably warm temperatures persist along and south of the I-70 corridor. A recycling of moisture beneath the flat ridge is expected to fuel scattered showers and thunderstorms each afternoon and evening during the remainder of the week. GFS and EC were divided on whether similar conditions will continue into the weekend. The dry GFS suggested that another passing short-wave trough will spread drier air over the forecast area in its wake ending afternoon/evening moist convection. The ECMWF indicated less influence from the short-wave and thus continued activity during the hotter part of the day into the weekend. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) Issued at 302 AM MDT Mon Jun 20 2016 Very hot temperatures will cause density altitude to spike this afternoon. Because of this, engine characteristics will be affected as performance suffers. A few showers and storms will fire over the Continental Divide and San Juans and will be high based so expect some gusty winds from these features. At this time, do not anticipate any problems at TAF sites. && .FIRE WEATHER... Issued at 330 PM MDT Sun Jun 19 2016 A disturbance passing to the north of the forecast area on Tuesday will bring a cool front to the northern fire weather zones during the afternoon. The cool front will not arrive in time to bring down temperatures, but will generate gusty west winds ahead of it which, when combined with low relative humidity, may result in critical fire weather conditions. Therefore, a watch has been issued for the lower elevation fire weather zones of northwest Colorado from noon through 8 PM MDT on Tuesday. && .HYDROLOGY... Issued at 330 PM MDT Sun Jun 19 2016 Above normal temperatures will continue for the next several days at least. These high temperatures will exacerbate the melting of the remaining high elevation snowpack. Meanwhile, releases from area dams and management of water diversions will likely add to flow in some rivers and streams. As a result, waterways across the area will continue to run high, fast, and cold through the coming week. Stay advised of the latest river forecasts by visiting our website at weather.gov/gjt. && .GJT Watches/Warnings/Advisories... CO...Fire Weather Watch from Tuesday afternoon through Tuesday evening for COZ200-202. UT...None. && $$ SHORT TERM...TGR LONG TERM...NL AVIATION...TGR FIRE WEATHER...NL HYDROLOGY...TGJT
Area Forecast Discussion National Weather Service Grand Junction CO 1127 PM MDT SUN JUN 19 2016 .SHORT TERM...(This evening through Monday night) Issued at 330 PM MDT Sun Jun 19 2016 High pressure remained stretched across the Desert Southwest to the central High Plains today. Some mid and high clouds showed up overnight extending southwest to northeast across northeast Utah and northwest Colorado. Models indicated roughly 0.5 of an inch precipitable water corresponding to the cloud field. This high based moisture appeared insufficient to fuel even isolated storms over the higher terrain late this afternoon and early evening. As temperatures fall this evening, convective clouds will dissipate leaving clear skies over the region. Strong radiational cooling will provide quick relief from unseasonable afternoon heat. Another hot day in store Monday as high pressure persists over the region. Model guidance continued to forecast record or near record heat with a number of valley locations expected to reach 100 degrees or more. Marginal flow beneath the ridge suggests light terrain driven winds. Meanwhile, relatively moist air over the eastern Colorado plains is drawn westward toward the surface heat low centered over northeast Arizona. This will result in isolated to widely scattered thunderstorms along the Continental Divide during the afternoon. This high based moist convection will generate little measurable rainfall and strong outflow winds. Expect diurnal cooling to bring this activity to a halt around sunset with clearing during the remainder of the night. Overnight lows for early Tuesday morning will be just a degree or two milder than last night on average. .LONG TERM...(Tuesday through Sunday) Issued at 330 PM MDT Sun Jun 19 2016 Near record heat will continue Tuesday as high pressure remains over the area. Meanwhile, models indicated a passing short-wave trough to the north will flatten the ridge while driving a cool front across the northern zones late in the day. The front will not arrive early enough to bring cooling, but will enhance gradient winds north of the I-70 corridor. Elsewhere, moisture infiltrating the ridge from the east and south will fuel scattered afternoon/evening showers and thunderstorms, mainly over higher terrain. Cooler temperatures are in store across the north from Wednesday onward as the front stalls along the Roan Plateau and the Flat Tops, while unseasonably warm temperatures persist along and south of the I-70 corridor. A recycling of moisture beneath the flat ridge is expected to fuel scattered showers and thunderstorms each afternoon and evening during the remainder of the week. GFS and EC were divided on whether similar conditions will continue into the weekend. The dry GFS suggested that another passing short-wave trough will spread drier air over the forecast area in its wake ending afternoon/evening moist convection. The ECMWF indicated less influence from the short-wave and thus continued activity during the hotter part of the day into the weekend. && .AVIATION...(For the 06Z TAFS through 06Z Monday evening) Issued at 1125 PM MDT Sun Jun 19 2016 Expect VFR conditions to persist through the next 24 hours. Near record warmth will negatively impact AIRCRAFT performance, especially at the higher elevation airports across the region. Winds will remain relatively light and terrain driven. Isolated thunderstorms are expected to develop along the Continental Divide during the afternoon producing strong erratic outflow winds. && .FIRE WEATHER... Issued at 330 PM MDT Sun Jun 19 2016 A disturbance passing to the north of the forecast area on Tuesday will bing a cool front to the northern fire weather zones during the afternoon. The cool front will not arrive in time to bring down temperatures, but will generate gusty west winds ahead of it which, when combined with low relative humidity, may result in critical fire weather conditions. Therefore, a watch has been issued for the lower elevation fire weather zones of northwest Colorado from noon through 8 PM MDT on Tuesday. && .HYDROLOGY... Issued at 330 PM MDT Sun Jun 19 2016 Above normal temperatures will continue for the next several days at least. These high temperatures will exacerbate the melting of the remaining high elevation snowpack. Meanwhile, releases from area dams and management of water diversions will likely add to flow in some rivers and streams. As a result, waterways across the area will continue to run high, fast, and cold through the coming week. Stay advised of the latest river forecasts by visiting our website at weather.gov/gjt. && .GJT Watches/Warnings/Advisories... CO...Fire Weather Watch from Tuesday afternoon through Tuesday evening for COZ200-202. UT...None. && $$ SHORT TERM...NL LONG TERM...NL AVIATION...TGJT FIRE WEATHER...NL HYDROLOGY...TGJT Area Forecast Discussion National Weather Service Denver/Boulder CO 340 PM MDT MON JUN 20 2016 .SHORT TERM...(This evening through Tuesday) Issued at 340 PM MDT Mon Jun 20 2016 Low clouds remained over much of northeast Colorado through the afternoon, keeping temperatures on the plains too cool to support shower development. Afternoon shower activity up to this point has been limited to Park and Clear Creek Counties where thunderstorms have been slow moving up to this point. This area along with Douglas and Elbert Counties should be the least stable through the evening. Thunderstorms should last for another 4 to 6 hours and then dissipate. Locally heavy rain will be the primary threat from showers along with some small hail and gusty outflow winds. For Tuesday, the upper ridge strengthens over the state and warmer air moves back over the state. High temperatures across the plains are expected to jump back into the mid and upper 90s. Mountain areas should be the only ones to see any afternoon showers. .LONG TERM...(Tuesday night through Monday) Issued at 340 PM MDT Mon Jun 20 2016 Expect showers and thunderstorms Tuesday evening, mainly over the high terrain and south of I-70 over the plains before a cold front pushes south over the area around or after midnight. These storms will be high based and likely produce gusty winds. With the hot day followed by breezy conditions from the cold front, Tuesday nights low temperatures will likely be warmer than tonights along with poor humidity recoveries. The front will bring relief Wednesday from the near record temps. Look for temperatures to be about 8 to 10 degrees cooler over the plains and 5 to 8 degrees cooler over the high terrain. Residual moisture combined with a weak shortwave aloft will bring another day of afternoon and evening thunderstorms, focusing over the high terrain and western and southern urban corridors due to upslope flow. Flow aloft will begin transitioning to southwest Thursday and Friday as an upper trough pushes into the Pacific Northwest, which will bring in warming temperatures again. The surface high over the Great Plains will push east Thursday as a surface trough deepens on the lee of the Rockies. The residual moisture under the ridge will again spark into afternoon and evening convection these days, moving off the high terrain and over the plains as the surface trough deepens. The upper trough is expected to pass north of the area this weekend, sending a cold front down over the area for cooler temperatures back near normal values. This front may push through the area late Friday night. Readings should be in the mid 80s for the plains and in the upper 60s to lower 70s in the mountains. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) Issued at 340 PM MDT Mon Jun 20 2016 Continuing cloud cover is helping keep temperatures cool and therefore keeping the airmass too stable to produce showers at KDEN and KBJC. Radar is showing some showers that might cross over KAPA for the next few hours. Impacts at KDEN might be limited to wind shifts from thunderstorm outflow over the southern Denver Metro area. Winds are expected to shift to drainage southerlies overnight with ceilings dissipating. Warmer temperatures are expected tomorrow which should be warm enough to suppress most afternoon convective activity. && .BOU Watches/Warnings/Advisories... None. && $$ SHORT TERM...Dankers LONG TERM...Kriederman AVIATION...Dankers
Area Forecast Discussion National Weather Service Denver/Boulder CO 340 PM MDT MON JUN 20 2016 .SHORT TERM...(This evening through Tuesday) Issued at 340 PM MDT Mon Jun 20 2016 Low clouds remained over much of northeast Colorado through the afternoon, keeping temperatures on the plains too cool to support shower development. Afternoon shower activity up to this point has been limited to Park and Clear Creek Counties where thunderstorms have been slow moving up to this point. This area along with Douglas and Elbert Counties should be the least stable through the evening. Thunderstorms should last for another 4 to 6 hours and then dissipate. Locally heavy rain will be the primary threat from showers along with some small hail and gusty outflow winds. For Tuesday, the upper ridge strengthens over the state and warmer air moves back over the state. High temperatures across the plains are expected to jump back into the mid and upper 90s. Mountain areas should be the only ones to see any afternoon showers. .LONG TERM...(Tuesday night through Monday) Issued at 340 PM MDT Mon Jun 20 2016 Expect showers and thunderstorms Tuesday evening, mainly over the high terrain and south of I-70 over the plains before a cold front pushes south over the area around or after midnight. These storms will be high based and likely produce gusty winds. With the hot day followed by breezy conditions from the cold front, Tuesday nights low temperatures will likely be warmer than tonights along with poor humidity recoveries. The front will bring relief Wednesday from the near record temps. Look for temperatures to be about 8 to 10 degrees cooler over the plains and 5 to 8 degrees cooler over the high terrain. Residual moisture combined with a weak shortwave aloft will bring another day of afternoon and evening thunderstorms, focusing over the high terrain and western and southern urban corridors due to upslope flow. Flow aloft will begin transitioning to southwest Thursday and Friday as an upper trough pushes into the Pacific Northwest, which will bring in warming temperatures again. The surface high over the Great Plains will push east Thursday as a surface trough deepens on the lee of the Rockies. The residual moisture under the ridge will again spark into afternoon and evening convection these days, moving off the high terrain and over the plains as the surface trough deepens. The upper trough is expected to pass north of the area this weekend, sending a cold front down over the area for cooler temperatures back near normal values. This front may push through the area late Friday night. Readings should be in the mid 80s for the plains and in the upper 60s to lower 70s in the mountains. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) Issued at 340 PM MDT Mon Jun 20 2016 Continuing cloud cover is helping keep temperatures cool and therefore keeping the airmass too stable to produce showers at KDEN and KBJC. Radar is showing some showers that might cross over KAPA for the next few hours. Impacts at KDEN might be limited to wind shifts from thunderstorm outflow over the southern Denver Metro area. Winds are expected to shift to drainage southerlies overnight with ceilings dissipating. Warmer temperatures are expected tomorrow which should be warm enough to suppress most afternoon convective activity. && .BOU Watches/Warnings/Advisories... None. && $$ SHORT TERM...Dankers LONG TERM...Kriederman AVIATION...Dankers
  [top] Area Forecast Discussion National Weather Service Grand Junction CO 314 PM MDT MON JUN 20 2016 .SHORT TERM...(Tonight through Tuesday night) Issued at 313 PM MDT Mon Jun 20 2016 High pressure will continue to be anchored over the region for the next few days. As a result near record high temperatures are expected again on Tue, with highs possibly topping out a couple degrees warmer than today. Moisture will begin to move up from the south on Tue. This will increase the chance for thunderstorms over the southern Mountains. Any storms that develop will generally be high based and lightning may produce fire starts. See Fire Weather Discussion below. In addition, over the northern edge of the forecast area the gradient winds will increase as a disturbance passes over the northern Rockies. Nighttime lows will be a little warmer. But there will still be wide spreads between daytime highs and nighttime lows, as much as 30-40 degrees. .LONG TERM...(Wednesday through Monday) Issued at 313 PM MDT Mon Jun 20 2016 High pressure will stretch out across the entire southern half of the CONUS with the high center shifting to our southeast. This will allow some moisture to move up from the south for a better chance of mainly mountain, and mainly afternoon showers and thunderstorms for Wed and Thu. A low pressure system will then move onshore over the Pacific Northwest and across the northern tier states through the remainder of the period. The southern end of this trough is progged to brush our area by the end of the week. This should result in cooler temperatures, but also stronger winds. Little moisture is associated with this trough, so could result in fire weather concerns. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday afternoon) Issued at 313 PM MDT Mon Jun 20 2016 A few showers and thunderstorms will be possible over the San Juans until around 03z. Any storms that develop will be high based so expect some gusty winds from these cells. Isolated to scattered thunderstorms will then develop again over the southern and central Colorado mountains after 18z Tue. At this time, do not anticipate any problems at TAF sites through the next 24 hours and VFR conditions will persist. However, near record heat will negatively impact AIRCRAFT performance, especially for the higher altitude airports. && .FIRE WEATHER... Issued at 313 PM MDT Mon Jun 20 2016 A disturbance passing to the north of the forecast area on Tuesday will bring a cool front to the northern fire weather zones during the afternoon. The cool front will not arrive in time to bring down temperatures, but will generate gusty west winds ahead of it which, when combined with low relative humidity, may result in critical fire weather conditions. Therefore, a Fire Weather Watch remains in effect for the Little Snake and White River fire weather zones of northwest Colorado from noon through 8 PM MDT on Tuesday. In addition, moisture will begin to seep up into southwest Colorado. Scattered thunderstorms are forecast to develop over the western San Juan Mountains during the afternoon. These storms will be the first storms after a prolonged dry and hot period...and may produce fire starts with any lightning that occurs. Therefore a Fire Weather Watch has also been issued for the western San Juan Mountains for Tuesday noon through 8 PM MDT. && .HYDROLOGY... Issued at 313 PM MDT Mon Jun 20 2016 Above normal temperatures will continue for the next several days at least. These high temperatures will exacerbate the melting of the remaining high elevation snowpack. Meanwhile, releases from area dams and management of water diversions will likely add to flow in some rivers and streams. As a result, waterways across the area will continue to run high, fast, and cold through the coming week. Stay advised of the latest river forecasts by visiting our website at weather.gov/gjt. && $$ SHORT TERM...EH LONG TERM...EH AVIATION...EH FIRE WEATHER...EH HYDROLOGY...TGJT