Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 292350 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 650 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 629 PM EST Tuesday...Current radar shows light rain across our Eastern Vermont zones and temperatures above freezing across the entire area. Showers will continue for the next few hours, especially across Southeastern Vermont. Otherwise mainly just cloudy with light winds across the North Country. Some fog development is expected after recent rainfall and with small dewpoint depressions and light winds. Previous discussion follows. Generally looking for -RA to end across central/Eastern 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 Northward across PA at 15Z Wed, with the warm front reaching central NY and Western 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 Eastern slopes of the Greens, where localized 1" amts are expected. Mild temps on Wednesday...with highs mainly mid-upper 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 Western slopes of the Green Mountains with possible downslope effects. Otherwise, higher gusts should be confined to the exposed higher terrain areas of the Green Mountains 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/... 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. && .LONG TERM /FRIDAY THROUGH TUESDAY/... 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. && .AVIATION /00Z Wednesday THROUGH Sunday/...
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Through 00Z Thursday...A mix of mvfr, ifr, and lifr conditions prevail across our taf sites this evening. The highest potential for prolonged period of ifr/lifr conditions with cigs below 400 feet and vis < 1sm will occur at slk/mss tonight. Meanwhile...thinking ifr cigs develops at mpv/rut/btv associated with low clouds and areas of drizzle and fog by 06z. Fog and mist will continue across the mountains...causing the terrain to be obscured. Radar shows areas of light rain may still impact rut/mpv through 03z...before shifting to our east. Difficult to determine when cigs/vis improve on Weds...ahead of our next weather system which arrives on Weds afternoon. Thinking mvfr with some vfr conditions develop by 16z...especially btv/pbg/rut...before rain arrives after 18z...with mvfr/ifr redeveloping by evening. Light terrain driven winds tonight will become southeast on Weds...with a few localized gusts to 25 knots at rutland after 18z. Outlook 00z Thursday through Sunday... Widespread rain with embedded periods of moderate rain will impact our taf sites through 12z Thursday...with mvfr cigs/vis and occasional ifr conditions likely. Gusty southeast winds are possible along the western slopes...and will impact rutland with gusts up to 30 knots possible. Winds shift to the west/southwest by Thursday morning with some localized gusts up to 30 knots possible at slk/mss. These strong wind profiles and changing winds with height will cause areas of low level turbulence and shear. A slow clearing trend is anticipated with ifr conditions becoming mvfr on Thursday into Friday. Mainly mvfr will prevail in the mountain taf sites and a mix of mvfr/vfr in the valleys through the upcoming weekend.
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&& .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Banacos NEAR TERM...Banacos/Neiles SHORT TERM...WGH LONG TERM...WGH AVIATION...Taber is the U.S. government's official web portal to all federal, state and local government web resources and services.