Scientific Forecaster Discussion
fxus61 kbtv 122353
Area forecast discussion
National Weather Service Burlington Vermont
653 PM EST Tue Nov 12 2019
much colder air pushes into the area tonight behind departure
of low pressure system which brought snow and mixed
precipitation to our region. Unseasonably cold and mainly dry
weather then persists across the area through much of the week
before temperatures moderate into next week.
Near term /through Wednesday night/...
as of 653 PM EST Tuesday...overall only minor adjustments
needed to the forecast for the overnight hours. Lingering low
level moisture and stiff westerly winds continue to create
scattered to broken clouds and a few snow showers across
northern portions of the forecast area this evening, and that
trend will continue through much of the overnight as surface
high pressure over the Ohio Valley is slow to edge eastward and
aloft the base of an upper trough is still yet to traverse the
northeast. Valley locations will see the least amount of sky
cover tonight owing to downsloping, with the Adirondacks and
central/northern Vermont remaining more cloudy. Clouds won't
hinder strong cold air advection dropping temps well below
seasonal normals though with lows early Wednesday morning in the
single digits to locally teens above zero in the Champlain
upper level low and core of cold air heads towards northern New
York and Vermont overnight. 850 temps will dip to about -20 c.
There may be some lingering light snow showers or flurries
across the higher terrain as upper level trough crosses the
area. Occasional light snow showers and flurries are also likely
downwind of Lake Champlain where lake induced cape values will
exceed 500 j/kg. Some light/minor snow accumulations are
possible in these areas. Low temperatures will dip into the
single digits above and below zero, lower teens close to Lake
Champlain. These low temperatures will likely set new record low
Any lingering snow showers or flurries will end Wednesday
morning as ridge of surface high pressure builds over the area.
Winds will become weak and will see partly to mostly sunny skies
by the afternoon. High temperatures will also be very cold for
mid November, with Max temperatures reaching the teens to lower
20s. These values are around 25 degrees below seasonal normals.
Surface high will crest atop the north country around 00z Thu,
leading to another unseasonably cold night Wednesday night even
though deepest core of cold air lifts north and away from the
area. Some shortwave energy headed towards the St Lawrence
Valley by early Thu morning will keep some clouds over the
region and prevent temperatures from bottoming out as much as
they potentially could. Mins will range from the single digits
above zero to the lower teens, warmest near Lake Champlain and
in the St Lawrence Valley.
Short term /Thursday through Thursday night/...
as of 305 PM EST Tuesday...a weak shortwave trough will pass
north of the forecast area Thursday. As previously mentioned,
this shortwave will be decaying as it moves eastward, therefore
only anticipating light snow showers mainly across the St
Lawrence Valley and along the international border...areas that
do see any accumulation are only looking at between a dusting
and 0.50" with the highest amounts for the St Lawrence Valley
and Jay Peak. Thursday high temperatures will be much more mild
compared to previous days with highs in the upper 20s to low 30s
under generally light southerly winds.
With clouds and precipitation around Thursday night, low
temperatures won't drop too far from their daytime highs with lows
in the mid to upper 20s to around 30 near the immediate Lake
Champlain shoreline. Additional snow showers are possible downwind
of Lake Ontario across the immediate St Lawrence Valley as lake-
effect gets going...any new snowfall amounts will be generally
around 0.50" through Friday morning.
Long term /Friday through Tuesday/...
as of 305 PM EST Tuesday...the main story for the extended will
be another shot of frigid air for the first part of the weekend
as a sharp cold front crosses the area Friday night. Rain and
snow showers are likely ahead of the frontal boundary during the
day on Friday. Still some questions on how quickly temperatures
will drop behind this front Friday night. GFS solution is the
fastest with temperatures dropping quickly into the teens behind
the front. Given cold bias on the GFS has settled on a blend
with temperatures still dropping into the 20s but not as
quickly. We'll have to refine this forecast in the next couple
days as a flash freeze may be possible if GFS solution pans out.
After this front, temperatures begin to moderate going into next
week with above normal temperatures likely in the 8-14 day outlook
from CPC. In addition to above normal temperatures, drier weather is
expected during this timeframe as upper level riding builds in.
Aviation /00z Wednesday through Sunday/...
through 00z Thursday...other than some lingering MVFR and light
snow at kslk through the early overnight, VFR conditions will
largely prevail through the period with general clearing in the
deeper valleys and higher terrain remaining sct-bkn. Stiff
westerly winds gusting to 18-22kts this evening gradually abate
by midnight, but remain in the 5-10kt range thereafter through
Wednesday before trending calm by 00z Thursday.
Wednesday: VFR. Slight chance shsn.
Wednesday night: VFR. Slight chance shsn.
Thursday: VFR. Slight chance shsn.
Thursday night: VFR. Slight chance shsn.
Friday: mainly VFR, with local MVFR possible. Likely shra, chance
Friday night: mainly VFR, with local MVFR possible. Slight chance
Saturday: VFR. No sig weather.
below are daily record minimum temperatures for November 13 and 14.
November 13 November 14
Burlington: 15 (1986) 10 (1996)
plattsburgh: 10 (1986) 12 (2004)
montpelier: 10 (1986) 5 (2018)
Saranac lake: 2 (1905) -4 (2018)
massena: 12 (1986) 8 (1971)