549 FXUS61 KBTV 211626 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 1126 AM EST Sat Nov 21 2020 .SYNOPSIS... A relatively non-eventful cold front will continue to push through the North Country today. This front will bring mainly an increase in cloudiness with isolated drizzle or flurries possible. Our next system arrives late Sunday through Monday bringing the possibility of rain, snow, sleet and freezing rain to the region. Near normal temperatures are expected through much of next week. The active pattern continues with chances for another storm system to arrive by midweek. && .NEAR TERM /THROUGH SUNDAY/... As of 1124 AM EST Saturday...Main adjustment was to bump hourly temperatures up a few degrees since we remain in the mid 40s over much of our region. Cold advection should do its job shortly, and blended this into the previous forecast. Otherwise, began making tweaks in preparation for the TAF package. The forecast is in great shape! Have a great day! Previous Discussion...Today will feature increasingly cloudy skies as a weak cold front moves through the North Country. Still continuing with the idea that a few sprinkles/flurries may be possible, mainly across the west/northwestern slopes of the Adirondacks. No accumulations are expected, with a most a dusting expected. Highs today will be near seasonable in the upper 30s mountains/low to mid 40s elsewhere under generally light SW/W winds this morning switching to the NW late this afternoon. Surface high pressure quickly moves in overnight, with clear skies expected. Overnight lows should dip into the mid teens/low 20s across the area. With fast zonal flow remaining aloft, high pressure scoots rapidly to the east by tomorrow afternoon as our next system approaches from the west. Surface winds begin to shift out of the E/SE under increasingly cloudy skies. Precipitation is expected to move into the southwestern corridor of the St Lawrence valley towards 21z and spread eastward into VT towards 00z. Precipitation should initially fall as a mix of rain/snow but enough thermal cooling should take place give good dynamical forcing that it should change over to snow across the St Lawrence Valley. A mix of light rain/snow is expected across south/central VT depending on elevation. Accumulations will be generally light during this timeframe with 0.5-1" across northern New York and a dusting to 0.5" for mainly the spine of the Greens and hills of central VT. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... As of 416 AM EST Saturday...An active period of weather for the beginning of the week. Deepening low pressure will move from the Ohio River Valley northeastward, tracking along or just south of the St Lawrence Valley. Warm air will stream northward on a strong south jet, riding up and over colder air at the surface, resulting in a wintry mix of precipitation for much of the North Country. As always, the question is how long before the warmer air wins out over the colder air at ground level? There are still some differences in models as to exactly where the low tracks and the extent of the warm air, making for an even tricker forecast. The Champlain Valley will warm fastest as south winds will funnel the warm air northward. Hence expect just a short period of snow/sleet/freezing rain with little accumulation before the change over to rain occurs, roughly around midnight. In northern NY, the St Lawrence Valley will hold onto the wintry precipitation longest as northeast surface winds look to hold tough as often happens, especially in the northern portions of the valley. A low track over the St Lawrence Valley would allow more warmer air and more mix, while a track just south of the valley would keep the valley more snow and any mixed precipitation across the Adirondacks. Either way, these areas look to hold onto the mixed precipitation until very early Monday morning, perhaps past daybreak in the northern St Lawrence Valley. Snow accumulations of 1 to 4 inches would be possible in these areas, with ice accumulation less than a tenth of an inch. The surface cold air will also be tough to scour out in eastern VT, so the mixed precipitation would persist into early-mid morning Monday, lingering longest in the cold hollows of the Northeast Kingdom. Snow accumulation would be 2 inches or less with less than a tenth of an inch of ice. All locations will transition to plain rain for a time Monday with highs to be in the mid 30s to lower 40s. However, colder air will rush into the region from west to east through the day as the low drags its attendant cold front across the region. This will allow rain to change back over to snow, especially over the higher terrain. The widespread precipitation will become more terrain focused behind the front as well as winds turn to the northwest. These western-slope snow showers will linger into Monday night with temperatures dropping into the teens and 20s. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 416 AM EST Saturday...Drier weather will resume Tuesday into Wednesday as high pressure settles over the region. Temperatures will be colder than normal Tuesday and Tuesday night, but warming will begin Wednesday as low pressure approaches from the west. This low will also bring another round of precipitation, mainly late Wednesday into Thursday. Model solutions showing a bit of disagreement on how this low evolves, with the GFS taking it up to our northwest, with a wintry mix of precipitation turning to rain, much like the Sunday night-Monday event. The ECMWF and CMC meanwhile take a weaker low from the Midwest states eastward, over or just south of New England, perhaps developing a weak coastal low in the Gulf of Maine. This would be more of a snow-rain event for our region. Have stayed close to a model blend for the Wednesday night- Friday timeframe given these differences. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... Through 06Z Sunday...VFR ceilings will trend MVFR overnight as weak frontal boundary sags south out of Canada this morning. Ceilings will trend MVFR towards 12-14z from NW to SE and will generally be in the 2500ft range, although 1500ft ceilings are possible at KSLK. VFR ceilings will return toward 18z through the remainder of the period. Winds overnight will generally be light out of the south 5 knots of less, becoming W/NW between 5-10kt after 14z. Outlook... Sunday: VFR. Chance RA, Chance SN. Sunday Night: Mainly MVFR and IFR, with local VFR possible. Definite RA, Definite SN, Definite FZRA. Monday: MVFR/IFR conditions possible. Definite RA, Chance SHRA, Chance SHSN. Monday Night: Mainly VFR, with areas MVFR possible. Slight chance SHSN. Tuesday: Mainly VFR, with local MVFR possible. NO SIG WX. Tuesday Night: VFR. Slight chance SN. Wednesday: Mainly VFR, with local MVFR possible. Chance RA, Chance SN. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...LaRocca NEAR TERM...Haynes/LaRocca SHORT TERM...Hastings LONG TERM...Hastings AVIATION...LaRocca