Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 012035 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 335 PM EST Thu Dec 1 2016 .SYNOPSIS...
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A closed upper low over southern Quebec will keep the north country in cyclonic flow through Saturday, with cloudy skies and chances for rain and snow showers from tonight through Saturday. A ridge of high pressure will build into the region on Sunday, with fair and dry weather expected from Sunday through Tuesday.
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As of 335 PM EST Thursday...The closed upper low over southern Quebec will keep the north country in cloud cover overnight along with a chance of rain and snow showers, with snow showers confined to the higher elevations of the Adirondacks and Green Mountains. The combination of cloud cover and west-southwest winds will help to keep temperatures above freezing overnight. MOS guidance looks too cold for overnight min temperatures, so have leaned toward the warmer GFS LAMP mos guidance for min temperatures overnight. Winds will stay up overnight and this combined with the cloud cover will keep temperatures several degrees warmer than MOS guidance overnight. BTV 4KM model also suggesting that most of the lake effect showers off of Lake Ontario will remain south of the forecast area overnight. On Friday, the north country will continue to be under the influence of the closed upper low over southern Quebec which will keep in cloud cover, along with chances for rain and snow showers. Snow showers will be mainly confined to the higher elevations of the Adirondacks and Green Mountains. Highs will be mainly in the 40s on Friday
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&& .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... As of 311 PM EST Thursday...500mb trough moves through the region Friday night with snow showers expected about 1000ft and above and rain/snow mix at lower elevations transitioning to snow for the latter half of the night. Min temperatures will randing from the mid 20s to low 30s. As surface low pushes eastward toward the Canadian maritimes, a ridge of high pressure builds across the lower Ohio valley, putting the north country in NW flow. This will result in precipitation becoming more orographic by Saturday morning. FROUDE numbers of 0.5 to 1 indicate slow moving blocked flow on Saturday, helping to focus snowfall on western slopes and in the higher terrain. There`s a chance for brief disruption in flow late in the day as 500mb vort swings across the North Country, providing a slight chance to chance of mostly snow across the forecast area. Max temperatures on Saturday will remain in the 30s. Saturday night the surface ridge shifts eastward over the eastern Great Lakes by Sunday morning. Moisture over the North Country looks to diminish from top to bottom with lingering clouds under inversion. Expect snow showers to end by daybreak. Forecast snowfall totals throughout the short term are a dusting to quarter inch in the broad valleys, with few tenths of an inch to 3 inches in the higher elevations. Min temperatures generally in the 20s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 311 PM EST Thursday...High pressure is the dominant feature Sunday and Sunday night, resulting in a brief period of dry weather. Remaining under light northerly flow, temperatures remain cooler Sunday with maxes in the 20s to mid 30s. Min temperatures will range from the mid teens to mid 20s Sunday night. Another mid level trough arrives Monday morning, weakening as it moves across the region and resulting in only chance POPs as ridging returns Monday night. With max temperatures in the 30s, generally expect light snow showers. A more significant system takes form Tuesday, bringing in precipitation from the south and west. Still much disagreement among models, but as initial precip looks to be the result of warm air advection/warm front, there`s a chance for mixed precipitation Tuesday night into Wednesday. GFS shows southern stream low develop into closed coastal low moving near the 70/40 benchmark as another surface low associated with very large 500mb trough approaches the region from the west. 12Z ECMWF not available at time of forecast for comparison. && .AVIATION /20Z Thursday THROUGH Tuesday/... Through 18Z Friday...Mainly mostly cloudy skies expected through the period as the region remains under cyclonic flow from a closed upper low over Quebec. Expecting VFR with areas of MVFR ceiling with scattered rain and snow showers expected through the period. Snow showers will be mainly over the higher elevations of the Adirondacks and Green Mountains. West- southwest surface winds will gust from 15-25 knots through the period. Outlook 18Z Friday through Tuesday... 18Z Friday through 18Z Sunday...Mix of VFR/MVFR with local IFR at KSLK in scattered rain/snow showers. 18Z Sunday through Monday...Mainly VFR with high pressure building in. Periods of MVFR ceilings possible. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...WGH NEAR TERM...WGH SHORT TERM...KGM LONG TERM...KGM AVIATION...WGH is the U.S. government's official web portal to all federal, state and local government web resources and services.