Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 292055 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 355 PM EST Tue Nov 29 2016 .SYNOPSIS... An initial wave of low pressure will exit to our north and east this evening, allowing steady precipitation to end from west to east early tonight. Skies will remain cloudy with patchy drizzle and fog developing overnight. Another wave of low pressure and associated warm front will bring additional moderate rainfall to the North Country Wednesday afternoon through Wednesday night, along with locally gusty south to southeast winds. Rainfall amounts between a half and three- quarters of an inch are generally expected. A large upper trough will then persist across New York and New England, providing mostly cloudy skies and chances for rain showers Thursday and Friday, and scattered snow showers for the weekend. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... As of 206 PM EST Tuesday...Will allow the Freezing Rain Advisory to expire on time at 21Z with temps generally above freezing as of 19Z across central/ern VT. Just a couple of mesonet sites and KVSF still at 32F, with just a chance of some ice still around on untreated surfaces, especially in the deeper/more sheltered valleys. Elsewhere, temps have generally risen into the low-mid 40s, except locally in the upr 30s with nely terrain channeled flow locked in across the immediate St Lawrence Valley of far northern New York. Per IR satellite imagery, initial shortwave trough is exiting to the north and east at 1930Z. Rainfall as already ended generally across the St. Lawrence Valley and nrn Adirondacks, and anticipate back edge of rainfall to shift slowly ewd per mesoscale model suite. Generally looking for -RA to end in the Champlain Valley around 00Z, and eventually end across central/ern VT 01-03Z. Once this happens, sea-level pressure field becomes nearly flat across our region, and weak flow regime with saturated conditions will prevail thru the remainder of the overnight hrs into Wed morning. Looking at continued low stratus deck, with some patchy drizzle and fog expected...right thru 14-15Z Wednesday with little flow to mix out near surface inversion layer. Temps quasi-steady tonight, mainly holding in the upper 30s to lower 40s. Meanwhile...developing surface low across the upper Ohio Valley and ewd extending, strong warm front will be lifting nwd across PA at 15Z Wed, with the warm front reaching central NY and wrn MA by 21Z Wed. Strong low- level WAA and isentropic ascent will overspread the North Country from south to north Wednesday afternoon into Wednesday evening, with surface low tracking to our west into southeastern Ontario during Wednesday night. PoPs near 100% Wednesday evening with periods of moderate rain expected. Total rainfall by 12Z Thursday generally 0.50-0.75", but 900-800mb SE flow increasing to 50-60kts will allow for some orographic enhancement on the ern slopes of the Greens, where localized 1" amts are expected. Mild temps on Wednesday...with highs mainly mid-upr 40s, and lower 40s for Wednesday night. Only other issue will be possible period of gusty winds, as SE 925mb flow increases to 40-45kts around 00-03Z Thu, per 12Z NAM, just in advance of the warm front. Anticipate steady rainfall during this time frame, which tends to lead to stable PBL conditions mitigating downward mixing and momentum transfer. Did include some SE winds 20-25mph with gusts to 35mph on the immediate wrn slopes of the Green Mtns with possible downslope effects. Otherwise, higher gusts should be confined to the exposed higher terrain areas of the Green Mtns into the nrn Adirondacks, peaking during Wednesday evening. As surface low moves past, will see a band of strong SWLY 925mb winds of 45-50kts moving across the St. Lawrence Valley. This may also cause some gusty winds to 35-40mph around KMSS and the surrounding St. Lawrence Valley toward daybreak on Thursday. Will continue to monitor. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
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As of 355 PM EST Tuesday...Precipitation to wind down Thursday morning as secondary low pressure area moves into the Gulf of Maine, with more showery precipitation expected Thursday afternoon across the region. The region will remain under the influence of a closed upper low over Canada, which will bring a chance of rain or snow showers to the region Thursday night.
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&& .LONG TERM /FRIDAY THROUGH TUESDAY/...
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As of 355 PM EST Tuesday...The region will remain under the influence of an upper low over Canada, so have kept in chances for rain and snow showers from Friday through Saturday. Models showing upper ridge to build into the region Sunday through early Tuesday. Have gone with a dry forecast for Sunday and Sunday night. For Monday, models suggesting mainly dry conditions for Monday and Monday night, as both the GFS and ECMWF show an upper ridge building into the region. Have lowered superblend pops for Monday and Monday night to mesh with neighboring offices, but expecting mainly dry conditions for Monday and Monday night. Models showing timing differences for Tuesday, with the GFS model bringing in precipitation Tuesday afternoon, while the ECMWF model holds off precipitation until Tuesday night. Have opted to hold off precipitation until Tuesday afternoon. Forecaster confidence for Tuesday is low, given model timing differences.
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&& .AVIATION /20Z Tuesday THROUGH Sunday/... Through 18Z Wednesday...Widespread IFR-MVFR conditions through the period. Light rain and patchy freezing rain far eastern VT will gradually end from west to east late this afternoon/evening. Will see prevailing low stratus and patchy fog overnight with diminishing winds areawide and TRRN OBSCD. Generally expecting widespread IFR 04-14Z Wednesday, with some improvement back to VFR possible locally at BTV 14-18Z Wednesday. Most other TAF locations should remain IFR/MVFR. Warm front approaching from the south with the next frontal wave will bring developing rainfall from south to north right at the end of the TAF period. Included VCSH at SLK/RUT for this developing rain, but majority will hold off until beyond 18Z Wednesday. Outlook 18Z Wednesday through Sunday...Widespread moderate rainfall with combination of MVFR/IFR conditions 18Z Wed through 12Z Thursday. Also, localized SE wind gusts in excess of 25kts possible KRUT 23Z Wed thru 05Z Thu, along with areas of LLWS areawide. Isold to sct showers remain possible Thu/Fri with VFR/MVFR conditions, followed by isold/sct snow showers Friday night through Sunday with continued VFR-MVFR conditions, and perhaps brief IFR with passing snow showers at TAF locations. && .BTV WATCHES/WARNINGS/ADVISORIES...
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VT...None. NY...None.
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&& $$ SYNOPSIS...Banacos NEAR TERM...Banacos SHORT TERM...WGH LONG TERM...WGH AVIATION...Banacos

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