Colchester, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

324
FXUS61 KBTV 231212
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
712 AM EST Sat Nov 23 2024

.SYNOPSIS...
More elevationally dependent snow and rain will continue this
morning with greater precipitation amounts focused over central
and eastern Vermont. An increasingly breezy, upslope pattern
will support several inches of wet mountain snow through the
weekend in the northern Greens, with minor snow accumulations
possible through much of northeastern Vermont at lower
elevations. Additional precipitation will return as mainly rain
Monday night into Tuesday, with more uncertain chances towards
late week.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 711 AM EST Saturday...No substantial changes needed for
this update. With regards to the challenge of snow levels this
morning, it appears the snow level is generally around 1500 feet
but sensitive to intensity of precipitation. In Essex County,
Vermont, heavier precipitation has allowed rain to change to
snow in Maidstone at 900 feet elevation where roads are wet.
However, RT 114 in Canaan at 1700 feet elevation has become snow
covered. Meanwhile, VT-17 in Buels Gore at 2300 feet is
partially snow covered with temperatures below freezing, but RT
105 in Jay at 2100 feet is just wet with snow on grassy
surfaces. So generally accumulations moving through this morning
still look to be primarily in higher elevation passes with
valleys seeing a cold rain or very wet snow with no
accumulations on roads.

Previous Discussion...
Warm air advection aloft from the east pivoting around
deepening low pressure moving northward towards the Canadian
Maritimes is combining with low level convergent flow to bring
widespread light rain and high elevation snow early this
morning. Better ingredients for precipitation appear to stay in
eastern Vermont, especially northeastern areas, into the midday
hours, where PoPs are greatest and near 100% for a period of
time. Precipitation type will become a rain/snow mix in much of
central and eastern Vermont this morning as temperatures in the
mid 30s trend towards the low 30s. With antecedent warm road
temperatures and relatively low precipitation rates, do not
expect any notable travel issues with minimal accumulation, but
elevations above 2000 feet will become increasingly likely to
see snowy roads today. During the late morning hours,
precipitation chances increase more into the favored upslope
areas in northern Vermont with blocked flow and abundant low
level moisture.

Pronounced mid-level drying will move in from the west
gradually during the afternoon and evening. That drying will
lead to precipitation becoming more of a drizzle/snizzle
depending on elevation. Low level temperatures remain fairly
warm, consistent with 850 millibar temperatures near -3 celsius,
so concern for icy conditions is fairly low at this time. That
being said, overnight a push of colder air from the west may
support formation of icy roads given wet conditions from today.
At this time, sub- freezing surface temperatures look unlikely
in Vermont below 2500 feet, but more likely to be sub-freezing
across the Adirondack region from the high peaks westward. Then
during the day tomorrow, while snow levels will be quite a bit
lower than today, precipitation will be largely confined to the
northern Green Mountains and northeastern Vermont. Snow
character will be less concrete and more of a typical wet snow
by this point, and several inches of snow could accumulate, with
the strong westerly flow particularly favorable for Jay Peak.

Across the region, breezy conditions will be another story both
today and tomorrow on the backside of the strong low pressure
system to our northeast. Nothing overly windy is anticipated,
but frequent gusts between 30 and 40 MPH will be common today in
eastern portions of new York and much of central and eastern
Vermont, and then again on Sunday with the stronger winds
tending to be farther north.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
As of 330 AM EST Saturday...Relatively quiet short-term forecast
period as narrow surface ridge axis builds eastward across northern
NY into New England. During the first half of Sunday night, residual
cyclonic 700-500mb flow and shallow layer of high RH may allow for a
few lingering snow showers or flurries across n-central into nern
VT. Indicated 20-30 PoPs during the late evening with drying and
trend toward clearing skies, especially after midnight. Little or no
additional snow accumulation expected early Sunday night. Overnight
lows will generally be in the mid-upper 20s, except locally lower
20s in the northern Adirondacks closer to sfc ridge axis. Narrow
ridge axis builds across the North Country during the daylight hrs
on Monday. Looking for partly to mostly sunny conditions and
seasonably cool temperatures with valley highs generally in the
lower 40s. May see some increasing high clouds late in the day
across nrn NY associated with the next system approaching from the
Great Lakes region, but PoPs NIL.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 330 AM EST Saturday...We are monitoring two potential
precipitation events during the long- term forecast period. The first
arrives late Monday night into Tuesday as a frontal system
approaches from the Great Lakes, with primary sfc low tracking north
and west of the St. Lawrence Valley. Developing south winds and warm
advection should result in early lows Monday night, with rising
temperatures after midnight. Can`t rule out precipitation starting
as a wintry mix (sleet/freezing rain) in some of the colder valleys
prior to daybreak Tuesday, but overall trend will be for mixed
precipitation to change to rain with limited winter travel impacts,
especially after 12Z Tuesday. Temperatures rise from the low-mid 30s
early Tuesday morning to the low-mid 40s by Tuesday afternoon.
Should see 0.25-0.40" precipitation in most sections of the North
Country with this system, and indicated 80-90% PoPs most areas,
peaking during Tuesday morning.

Cold front pushes through with a shift to westerly flow Tuesday
night into Wednesday. Should see periods of light rain and snow
showers Tuesday night into Wednesday (PoPs 50-60%), with some light
snow accumulations possible, especially away from the Champlain
Valley. Best chance for light snow accumulations will be across the
northern Adirondacks and n-central into nern VT.

Current indications suggest a trend toward drier conditions late
Wednesday through Thanksgiving Day. Valley highs on Thanksgiving Day
generally 35-40F.

Coastal system Thanksgiving night into Friday will be the next
system to watch. Have seen considerable run-to-run variability
during the past couple of days, and the 00Z global deterministic and
ensemble guidance continues to show a large spread of solutions. A
flatter and more progressive system staying to our south continues
to be supported by the 00Z Canadian. The 00Z GFS suggests northern
fringe of precipitation shield may reach Rutland/Windsor counties
during the first half of Friday. On the other hand, the 00Z ECMWF
has a more amplified solution with a negative tilt 500mb trough and
sfc cyclogenesis inside the 40N 70W benchmark bringing accumulation
snowfall across much of VT and portions of northern NY on Friday
into Friday night. At this time, official forecast reflects ~40%
PoPs for Thursday night into Friday. Bottom line: those with holiday
travel plans across the region should continue to monitor the latest
forecasts as winter travel impacts remain possible Thursday night
thru Friday.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Through 12Z Sunday...Low ceilings are common at all terminals,
with cloud bases between 400 and 1600 feet. Where IFR conditions
are present, expect this to gradually improve with return to
MVFR conditions during the day at MPV, BTV, EFK, and RUT, most
likely in that order, while ceilings remain IFR at SLK.  Light
precipitation is likely primarily between 10Z and 20Z and
especially at EFK, MPV, and BTV. Mountain sites should tend to
remain MVFR or IFR throughout the period while lower elevation
terminals trend VFR this evening.

Light to moderate rain is ongoing at Vermont terminals, with
relatively low chances for precipitation through 18Z at PBG and
SLK, which could be a mix of rain and snow at SLK. Snow may
begin to mix with rain at MPV as well, but generally
precipitation type should be liquid at our terminals.
Precipitation will become limited to more scattered showers
from 18Z to 00Z.

Winds will be north-northwesterly and breezy. Ongoing gusts are
already 20 to 25 knots at several sites, with these conditions
becoming more widespread through the day. Wind direction will
trend westerly, first across northern New York as early as 18Z
and then tonight over Vermont. Depending on if/when winds at
the surface relax tonight, additional chances for low level
wind shear, especially at EFK/MPV/RUT, will be present after
00Z as strong west-northwesterly flow persists aloft.

Outlook...

Sunday: Mainly VFR, with areas MVFR possible. Chance SN, Slight
chance FZDZ.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Chance SHSN.
Tuesday: Mainly MVFR, with areas VFR possible. Definite SHRA.
Tuesday Night: Mainly MVFR, with local VFR possible. Chance SHSN,
Chance SHRA.
Wednesday: Mainly MVFR, with areas VFR possible. Chance SHRA,
Chance SHSN.

&&

.MARINE...
Very favorable northerly channeled flow has developed,
resulting in winds in excess of 25 knots along with gusts
exceeding 30 knots on the broad lake. Expect peak winds will
decrease along with wave heights just a bit by afternoon as
shallow inversion weakens during the day but steady winds near
25 knots will persist. Additional strong winds on the lake will
develop tonight into tomorrow as winds become more westerly.
Wave heights will be 2 to 4 feet for much of the next two days.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Kutikoff
NEAR TERM...Kutikoff
SHORT TERM...Banacos
LONG TERM...Banacos
AVIATION...Kutikoff
MARINE...