016 FXUS61 KBTV 082223 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 623 PM EDT Fri Oct 8 2021 .SYNOPSIS... Building high pressure over northern Maine will help to push a backdoor cold front across the region tonight into Saturday. This boundary will have limited fan fair, but temperatures will be cooler and more clouds are likely on Saturday. A weakening system will produce additional clouds with maybe a few sprinkles late Saturday night into Sunday. && .NEAR TERM /THROUGH SATURDAY NIGHT/... As of 614 PM EDT Friday...Light easterly/southeasterly flow developing over southern and eastern Vermont this evening as anticipated. Forecast on track to see the development of some low clouds in southern/eastern Vermont as low-level moisture is advected westward on onshore flow. All this handled nicely in grids with no major changes needed. Previous discussion follows. Crnt sfc analysis places weak backdoor cold frnt approaching the NEK of VT, while building 1028mb high pres is located over northern Maine. This boundary and associated high pres wl increase bl to 925mb se winds overnight at 15 to 25 knots, resulting in much less fog/br development. In addition, developing se upslope flow over central/eastern VT, wl help advect in better moisture along the spine of the Green Mtns with some areas of stratus possible overnight into Sat. Difficult to determine areal coverage of stratus, as models prog rh fields develop overnight and coverage upstream based on vis sat imagery is minimal. Some very patchy fog is possible acrs the dacks as winds decouple and skies remain clear. As high pres builds toward the NEK by 12z Sat, NAM 3km showing drying bl dwpts, which wl allow temps to drop into the u30s/l40s with mid 40s SLK to l/m 50s SLV/CPV. Saturday 1030mb high pres remains over northern Maine, while s/w energy and moisture lifts toward the Ohio Valley/central Great Lakes. The gradient btwn these two systems wl increase, resulting in south/southeast winds 5 to 15 knots on Saturday. In addition, llvl thermal gradient tightens with progged 925mb temps near 12C SLV to 7C NEK, supporting highs lower 70s SLV to lower 60s NEK/Eastern VT. Have noted the NAM12 and NAM 3KM both increasing moisture along the spine of the Green Mountains on Sat, associated with se upslope flow. Wl increase clouds for this area and keep temps slightly cooler. On Saturday night, s/w energy and mid level moisture in the southwest flow aloft approaches our western cwa aft 06z. Have continued to mention chc pops btwn 06-12z Sunday to cover this potential. Energy and moisture looks to weaken as it encounters strong high pres to the east, with just a few sprinkles possible over the CPV and parts of VT. Temps wl remain on the mild side with lows mid 40s to mid 50s most locations. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... As of 312 PM EDT Friday...Surface high pressure will slide eastward and away from the region on Sunday and an upper level shortwave will pass through our area bringing just a chance for some light rain showers especially over Northern New York. Easterly flow continues across Vermont east of the Greens and will lead to cooler maximum temperatures, generally upper 50s to lower 60s. Meanwhile, the rest of our region will have southwesterly flow and maximum temperatures will range from the lower 60s to upper 60s, warmest in the St Lawrence valley. Clouds will remain in place through the overnight and minimum temperatures will range from the upper 40s to mid 50s. && .LONG TERM /MONDAY THROUGH FRIDAY/... As of 312 PM EDT Friday...The long term portion of the forecast continues to look pretty quiet with warmer than normal temperatures and dry weather. There continues to be potential for Tuesday to be quite warm, with maximum temperatures ranging through the 70s. A weak low pressure system will push across our area on Wed, but only a chance for showers is anticipated with this feature with not a lot of forcing or moisture. Behind the low pressure system passing through the region on Wed, warm and dry weather will return for the rest of the work week. && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/... Through 18Z Saturday...VFR conditions with light winds are expected for the next 6 hours at all taf sites. A backdoor cold front approaching the region from eastern VT this evening will increase the gradient across our taf sites. This will result in stronger bl winds of 5 to 10 knots with higher values in the 400 to 600 feet above ground level to limit fog development overnight. In addition, increasing moisture on southeast upslope flow will result in some mvfr cigs toward midnight at MPV and possibly EFK. Soundings at SLK indicate lighter bl winds and potential for some mvfr/ifr vis in fog/br, so have tempo this into the taf btwn 07-11z. Otherwise, light and variable winds become southeast 5 to 10 knots overnight, except northeast at KMSS, before shifting to the southeast on Saturday. Outlook... Saturday Night: VFR. NO SIG WX. Sunday: Mainly VFR, with local MVFR possible. NO SIG WX. Sunday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Columbus Day: Mainly VFR, with local MVFR possible. NO SIG WX. Monday Night: Mainly VFR, with local IFR possible. NO SIG WX. Tuesday: Mainly VFR, with local IFR possible. NO SIG WX. Tuesday Night: VFR/MVFR conditions possible. Slight chance SHRA. Wednesday: Mainly MVFR, with local IFR possible. Slight chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Taber NEAR TERM...Duell/Taber SHORT TERM...Neiles LONG TERM...Neiles AVIATION...Taber