Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 09/17/16


Area Forecast Discussion
National Weather Service Denver/Boulder CO
845 PM MDT FRI SEP 16 2016 .UPDATE... Issued at 845 PM MDT Fri Sep 16 2016 Weak shower activity has continued this evening over Park County and the Palmer Divide, but with little in the way of any thunder. A weak upper level jet streak appears to be sustaining the showers at this point. Shower activity should be dissipated by midnight with clearing skies after that. Will update the zones to remove the mention of thunderstorms, but hang on to a couple more hours of showers over the Palmer Divide. Satellite pictures show clear skies over the northwest quarter of Colorado at this time, which is expected to spread eastward overnight. No other changes to the forecast are needed at this time. && .SHORT TERM...(This evening through Saturday) Issued at 104 PM MDT Fri Sep 16 2016 There is fairly decent amount of convective cloudiness over the mountians, foothills, Palmer and Cheyenne ridges. The Cumulus is pretty flat. There are no returns on the radars yet as well. The ACARS Soundings show a stable layer. Models have a weak west and southwesterly flow aloft tonight. A weak upper trough axis will move across Colorado through the day Saturday with northwesterly flow aloft behind it by afternoon. The QG Omega fields have a tad of weak upward synoptic scale energy for the CWA tonight, then fairly decent downward motion all of Saturday. You can see this pretty well on the water vapor picture right now. For moisture, there is some on the models tonight and Saturday. The precipitable water values are in the 0.25 inch range over the west to 0.75 inch over the east the first two periods. The is a tiny bit of CAPE over the foothills early this evening. There is some CAPE over the eastern half of the plains Saturday afternoon. The QPF fields have a small amount of measurable rainfall over the southern CWA tonight. They also had limited amounts of rainfall over the mountians and foothills right now. There is a tad indicated over much of the CWA on Saturday. For pops, will go 0-10%s this evening. Will go with 0- 20%s for Saturday afternoon. For temperatures, Saturday`s highs look to be 2-4 C warmer than this afternoon`s. .LONG TERM...(Saturday night through Friday) Issued at 104 PM MDT Fri Sep 16 2016 Exiting weak upper level trof on Saturday night over far Eastern Colorado may still kick of a few showers during the evening hours. QG fields showing decent downward forcing behind the trof Saturday night with clearing skies. Expect some gusty winds that develop over the mountains and east slopes Saturday night. Cross sections showing 25-35kt cross barrier flow along with subsidence that will produce the winds. Sunday and Monday will be characterized by a dry Northwest to West flow aloft over Colorado. A warming trend through this period as temperatures rise well into the 80s across lower elevations. The flow aloft shifts more Southwest on Tuesday and Wednesday with a slow increase in moisture levels from the Southwest. Will expect an increase in shower activity especially in the mountains by late Tuesday and Wednesday. The next West coast trof will move inland on Thursday and rapidly sweep across the Northern High plains on Friday. The best chance of showers will be on Thursday over Northern Colorado ahead of the trof and as moisture gets pulled up from the Southwest. Best moisture and dynamics will be North of Colorado so shower coverage on the plains may not be very extensive. Friday looks to dry out as stronger westerly flow develops. Cooling trend thorough the end of the week. Both GFS and European solutions are in better agreement today with the timing and amplitude of the trof. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 845 PM MDT Fri Sep 16 2016 Minimal aviation impacts are expected over the next 24 hours as a dry and stable airmass move over the state. Skies will become clear overnight with high cloud heights until then. Winds will become southerly over the next couple hours and remain that way through about midday on Saturday. && .FIRE WEATHER... Issued at 104 PM MDT Fri Sep 16 2016 Elevated fire weather danger expected on Sunday over far Northern Colorado, especially over high mountain parks and locations of Colorado bordering Wyoming. Stronger Northwest flow aloft develops over Colorado on Sunday as temperatures warm...and humidity levels drop to 15-20 percent by Sunday afternoon. Gusty Westerly winds will also surface in the afternoon with gusts possible up to 35 mph. && .BOU Watches/Warnings/Advisories... None. && $$ UPDATE...Dankers SHORT TERM...RJK LONG TERM...Entrekin AVIATION...Dankers FIRE WEATHER...Entrekin
Area Forecast Discussion
National Weather Service Buffalo NY
1023 PM EDT FRI SEP 16 2016 .SYNOPSIS... The weekend looks warm but a little gloomy with extensive cloud cover and several rounds of showers. As is often the case, there will likely be several periods of dry weather as well. Some of the showers may be accompanied by some thunder and lightning as a warm front moves north across the region on Saturday, followed by a weak cold front on Sunday. Dry weather will return for next week. && .NEAR TERM /THROUGH SATURDAY/... A well established upper level low continues to slowly move into the upper plains states this afternoon with a weak surface reflection underneath. Meanwhile, high pressure has moved off the east coast. Low level moisture has been surging north from the Gulf of Mexico for the past 24+ hours with fairly widespread thunderstorms over the central plains this afternoon. Further to the north, low level moisture is apparent near 925 mb per SPC/RAP analysis and continues to show itself through low cloud development throughout central PA. Tonight...with the loss of mixing after daytime heating, expect this moisture to surge further into NY with areas of low clouds developing or advecting north through the Southern Tier and possibly into the Niagara and Genesee river regions. This would quickly put any significant drop lowering temperatures overnight. Precipitation should hold off for all areas of WNY and CNY and still be upstream toward daybreak. Saturday...There will likely be at least two rounds of rain moving east across the region. Each will have enough lift for some embedded thunderstorms, although CAPE from point locations sport a tall and skinny profile. Shear is marginal at about 30kts, but extensive cloud cover should keep vertical updrafts relatively weak, and eliminate any hail threat yet still favor a potential for locally heavy rainfall. Latest high resolution models do not hint at any training though, and instead feature roughly two, perhaps three N-S oriented bands moving east across the region during the day with typical variations in time. The first round of precipitation, if it materializes, would be during the morning based off of some of the guidance. There is higher confidence for a second round moving in to WNY or developing along a weak inland convergent boundary and moving east across WNY. A third round may move into the region later in the afternoon. This scenario favors an overall high probability of precipitation for the day, but with plenty of dry time as well. The result will be a rather gloomy but still warm start to the weekend with little or no opportunity for sunshine. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... Moisture plume advances overhead Saturday night within deep layer southwest flow environment out ahead of main wave and surface cold front. Scattered to numerous showers will accompany this moisture, driven in large part by development of modest low level jet. A few rumbles of thunder cannot be ruled out with maintenance of some minimal most unstable cape, but severe threat looks to be nil. It will be a muggy night as we remain in the warm sector ahead of the approaching cold front. Most overnight lows holding in the mid 60s. On Sunday, we will remain warm and humid most of the day with the cold front gradually easing across the region. Moist low level air mass ahead of the front with surface dew points well into the 60s and heating after perhaps some low cloudiness burns off, leads to a decent signal for MLCAPE values in the vicinity of 1000J/kg over western and north-central New York. Forcing signal is not overly impressive, suggesting convective coverage will tend to be more scattered. Deep layer shear looks less than impressive, therefore potential for any severe weather looks limited, though a conditional threat exists for some gusty storms. The frontal boundary and supporting mid level trough axis will clear well east of the forecast area Sunday night with a wedge of Pacific based high pressure building overhead to start next week. Incoming drier air will bring a sharp end to most showers Sunday night with temperatures and dewpoints also easing back toward or just into the 50s. On Monday, high pressure will be centered over the Ohio Valley and bring a fine weather day to the region, with seasonable temperatures in the lower to mid 70s. && .LONG TERM /TUESDAY THROUGH FRIDAY/... A near zonal flow along the Canadian border during this period will mark the northern extent of a sub tropical ridge that will initially be centered over the Southern Plains. As we progress deeper into the week...the ridge will drift east and amplify over the Ohio Valley. This whole scenario will guarantee that our temperatures will average above normal throughout this period. In fact...the mercury will be roughly 10 deg F above 30 year norms with highs generally in the mid to upper 70s. These readings will be more typical of mid August. On a day to day basis... A weak cold front will cross our region on Tuesday. The aforementioned sub tropical ridge will block any GOMEX moisture from making its way int our region though...so the moisture starved frontal passage will only be accompanied by sparse shower activity. Will keep slgt to low chc pops in place. High pressure over the upper Mid West Tuesday night will then push east across the Lower Great Lakes for Wednesday. This will supply our region with a period of fine weather with light winds and comfortable temperatures. As the surface high moves off the Mid Atlantic Coast...a weak cold front will settle to the south across our region Thursday and Friday. Again...the front will be moisture challenged and with little frontogentic forcing expected...the opportunity for showers will be limited. Will continue to use slgt to low chc pops for the bulk of the region. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Low level moisture seen on 00hr model analysis at 925 and 850mb and a few upstream AMDAR locations continues to stream north into WNY this afternoon. An area of stratus and stratocumulus on the edges continues to move to/across the NY/PA state line this afternoon. Expect this trend to continue after dark with widespread MVFR and some IFR across the Southern Tier overnight, lasting right through Saturday. In terms of precipitation...expect 1 to 3 N-S oriented lines to move eastward across the region on Saturday with some temporary reductions to visibility. Some -TSRA will be possible with each line. The main impacts however will be the continued low cloud deck. Outlook... Saturday Night...MVFR with showers becoming likely...along with the chance for a few thunderstorms. Sunday...Conditions returning to mainly VFR with showers diminishing. Monday...VFR. Tuesday...Mainly VFR with a chance of showers. Wednesday...VFR. && .MARINE... Southerly winds will freshen tonight into Saturday ahead of an approaching cold front. While this will keep most of the wave action confined to Canadian waters this weekend, waves could approach small craft advisory-levels near the entrance to the Saint Lawrence River for much of the weekend, before winds decrease slightly and veer to the west behind the front Sunday night. Lighter winds on Monday should allow for wave action to diminish on the lakes before winds freshen and waves build once again Monday night into Tuesday. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Beach Hazards Statement from 2 AM EDT Saturday through Saturday afternoon for NYZ007. MARINE...Small Craft Advisory from 2 AM to 2 PM EDT Saturday for LOZ045. && $$ SYNOPSIS...WCH/ZAFF NEAR TERM...ZAFF SHORT TERM...TMA LONG TERM...RSH AVIATION...WCH/ZAFF MARINE...ZAFF