Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 200739 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 239 AM EST Mon Nov 20 2017 .SYNOPSIS... Snow showers will continue to linger across the North Country tonight...especially in the mountains. However...any accumulations will be light. Winds will remain gusty from the northwest. Relatively dry weather is expected on Monday...but temperatures will be below normal. Southerly flow quickly develops on Tuesday and sunshine...dry weather...and high temperatures in the 40s to around 50 returns to the area. && .NEAR TERM /THROUGH TUESDAY/... As of 1038 PM EST Sunday...Low-level CAA continues late this evening within moderately strong WNWLY flow regime across NY and northern New England. There is an embedded shortwave trough evident in IR imagery across sern Ontario and nrn NY, which will continue to migrate ewd along the intl border over the next several hours. Still seeing some intermittent light snow shower activity and scattered flurries associated with this feature and moist upslope flow...mainly across the Adirondacks and Green Mtns. However, any additional accumulation will be light across the mtns, generally a coating to 1". Otherwise, looking at overcast conditions with just a few flurries and continued moderately strong wnwly winds. May see a few breaks toward daybreak as shortwave trough passes to the east of our longitude. Forecast remains in good shape with just minor adjustments for hourly trends with this update. Previous discussion follows. Previous Discussion... Surface low and cold front are now north and east of the area this afternoon. Low level cold air advection continues with west to northwest flow with temperatures holding steady in the mid 20s to lower 30s in northern New York and in the mid 20s to mid 30s across Vermont. Thus any precipitation will be in the form of snow showers. In terms of precipitation...the vertical depth of moisture has decreased making for any precipitation to be on the light side. Webcams show this to be the case as well. In addition...west to northwest low level flow is helping to focus some of the precipitation in the mountains. Of note is the the increasing Froude numbers along the west slopes of the Green Mountains which suggests any upslope precipitation will be carried more downstream on the east side of the Greens. However...any additional snow amounts tonight will generally be an inch or less. Should still see quite a bit of cloud cover tonight with lows getting down into the mid teens to the mid 20s. On Monday...we remain in west to northwest flow in the morning with the flow gradually backing to the west throughout the day. This may allow some lake effect moisture to our south to lift up into our area...but may only affect parts of the northern Adirondacks and the southern half of Vermont. Below normal temperatures continue with highs generally in the mid 20s to mid 30s. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/... As of 239 AM EST Monday...Little change in the overall synoptic pattern is expected in the short term period where once again we`ll be dealing with another clipper low passing well north of the region, dragging a cold front through the area Tuesday night through Wednesday. Mild temperatures in the mid-30s to low-40s ahead of the front will support mainly rain in the valleys and a rain/snow mix at higher elevations as the boundary shifts into northern New York around midnight Wednesday, the morning rush in the Champlain Valley, and through eastern Vermont by mid-day. Behind the front, temps will gradually fall through the day with morning highs mainly in the mid/upper 30s, dropping to the upper 20s to mid 30s by sunset. Little to no snow accumulation is expected in the valleys, while elevations above 1000 feet may see a dusting to perhaps 2". && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... As of 239 AM EST Monday...Extended period remains fairly active with breaks of high pressure in between more clipper lows passing north of the area through central Ontario and Quebec. Quiet weather is expected under high pressure for Wednesday night through Thanksgiving with seasonal to slightly below normal temps in the 30s/40s for highs and teens/20s for lows. First of 2 cold fronts to swing through the area arrives Thursday night into Friday with little fanfare as the parent low will track well north of the region, starving the boundary of any real deep moisture. Thus, while the probability of precipitation is high, the overall QPF is low with likely just some scattered snow showers and little accumulation if any. Brief high pressure builds back in for late Friday afternoon into early Friday night before the next front approaches. While several days out, this system looks similar to the one we just had this past weekend with strong warm air advection, gusty southwesterly winds and rain ahead of the cold front on Saturday, sharply falling temperatures, rain changing to snow showers and potential flash freeze Saturday night, followed by a cold, brisk Sunday. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... Through 00Z Tuesday...Mix of VFR/MVFR ceilings as cyclonic west northwesterly flow continues over the region. Mountain showers may drop visibilities at SLK down to IFR as light snow should continue off and on through about 05z. Expect gusty winds as steep lapse rates promote mixing with gusts between 15-23kts at all TAF sites. By daybreak Monday anticipate all sites improving to VFR ceilings while the gusty winds remain. Late in the day Monday afternoon and evening SLK/MSS may become impacted by a lake effect snow band that will be lifting towards the north. With potential for varied intensity and timing, the forecast just mentions lowered ceilings rather than specific detail about visibilities. Outlook... Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA, Chance SHSN. Wednesday: Mainly VFR, with areas MVFR possible. Chance SHRA, Chance SHSN. Wednesday Night: Mainly MVFR, with areas VFR possible. Slight chance SHSN. Thanksgiving Day: Mainly VFR, with areas MVFR possible. NO SIG WX. Thursday Night: Mainly VFR, with areas MVFR possible. Slight chance SHSN. Friday: Mainly VFR, with areas MVFR possible. NO SIG WX. && .MARINE... As of 1125 AM EST Sunday...A Lake Wind Advisory remains in effect for today. Winds have turned to the northwest and are in the 25 to 35 knot range with gusts approaching 40 knots. This will create significant wave heights in the 2 to 5 foot range with a moderate chop. These conditions may prove hazardous to those operating small craft, especially on the eastern half of the broad lake and in Vermont bays/inlets with westerly exposures. Gusty northwest winds will abate slightly later this evening into Monday. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Evenson NEAR TERM...Banacos/Evenson SHORT TERM...Lahiff LONG TERM...Lahiff AVIATION...Deal MARINE...Evenson/JMG is the U.S. government's official web portal to all federal, state and local government web resources and services.