Williston, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

176
FXUS61 KBTV 131853
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
153 PM EST Tue Jan 13 2026

.WHAT HAS CHANGED...
As of 142 PM EST Tuesday...Slightly slower arrival of cold air on Weds
night into Thursday and a small increase in snowfall amounts over
northern New York, including the St Lawrence Valley.

&&

.KEY MESSAGES...
As of 142 PM EST Tuesday...

1. Gusty southerly winds overnight across the northern
Adirondacks and Champlain Valley, with much above normal
temperatures prevailing through Wednesday.

2. Sharply falling temperatures and rain changing to a
widespread light to moderate snowfall late Wednesday into
Thursday, will produce hazardous travel conditions.

3. Bitterly cold temperatures coupled with continued breezy winds
will lead to near dangerous wind chills Thursday night. Low
temperatures and breezy conditions continue into Friday Night.

4. Generally unseasonably cold temperatures will continue by the end
of this weekend into next weekend, with several chances for snow
showers, which could lead to slick travel at times.

&&

.DISCUSSION...
As of 142 PM EST Tuesday...
.Key Message 1: Gusty southerly winds overnight across the
northern Adirondacks and Champlain Valley, with much above
normal temperatures prevailing through Wednesday.

A period of gusty south to southwest winds 30 to 45 mph are expected
overnight acrs the northern slopes of the Adirondacks and the
central/northern Champlain Valley, which could cause a few power
outages. Sfc analysis shows 989mb low pres north of Lake
Superior, while 1020mb high pres is anchored off the East Coast.
As sfc low pres passes to our north overnight the 925mb to
850mb wind fields strengthen with progged 850mb winds of 50 to
60 knots and 925mb values of 40 to 45 knots. Sounding data
suggests a strengthening and lowering inversion around 2200
feet, which combined with favorable channeling on south flow wl
support gusts 35 to 45 mph northern CPV and parts of the
northern slopes near Malone. HREF shows a 80 to 100% probability
of wind gusts >40 mph, but only a small area of 20 to 35%
probability of gusts >45 mph.

GOES-19 water vapor shows embedded potent s/w energy over northern
MI, with cooling cloud tops on the IR satellite imagery moving into
the eastern Great Lakes this aftn. This moisture and dynamics wl
lift acrs northern NY and extreme northern VT tonight with a period
of precip likely. Progged 925mb temps hovering near 0C, support snow
levels around 1800 feet acrs the Dacks and northern/central Greens,
with rain showers in the valleys. Wind direction and speed wl once
again produce a rain shadow in the CPV, but would not be
surprised of a few light showers, given the dynamics. Snowfall
wl be a dusting to 2 inches with lows in the upper 20s to
mid/upper 30s.

.Key Message 2: Sharply falling temperatures and rain changing
to a widespread light to moderate snowfall late Wednesday into
Thursday will produce hazardous travel conditions.

Deepening mid/upper lvl trof acrs the central Great Lakes, combined
with sharpening low lvl thermal gradient wl help in the development
of sfc low pres late Weds into Thurs AM. Trends have been for a
slightly slower arrival of cold air, while delaying or shifting sfc
low pres development to the west. It should be noted there is still
a rather large spread in frontal timing and development and track
of sfc low pres on Weds night into Thurs, which greatly impacts
ptype and snowfall potential.

Given quick movement of system and potential for mid/upper lvl
dry slot, an advisory level event is likely for portions of our
region, especially northern NY and parts of central/northern
VT. NBM for at MSS indicates a 24 hour snowfall range of 0" for
the 25th percentile and 7" for the 75th, while the mean is 4".
Meanwhile at BTV the 25th is 1" and the 75th percentile is 5",
with the mean of 3". Did note the 00z/12z operational ECMWF and
12z GFS is showing an axis of enhanced qpf over northern NY
associated with mid lvl deformation and favorable low lvl
convergence as sfc low pres tracks over VT, which could produce
localized amounts near warning criteria. The progged 925mb temp
gradient associated with boundary is pretty impressive, which
should result in 10 to 15 degree sfc temp drop in 2 to 3 hours
on Thurs morning. This combined with rain changing to snow with
a period of accumulating snowfall likely near the Thurs morning
commute, wl result in locally hazardous driving conditions
likely.

For the CPV did note the Froude is very low 0.10 to 0.50
thru 16z Thurs, supporting snow upstream of the Green Mtns, but
wind direction is 250-270 degrees, which does not result in the
best convergence or moisture fetch off Lake Champlain to help
enhance snowfall locally. Bottom line expecting 2 to 7 inches
SLV/Northern Dacks to 1 to 5 inches most of VT, except locally
higher in the mtns, where change over occurs sooner. System
quickly lifts out of our cwa by 18z Thurs with some lingering
mountain snow showers and much cold temps, as progged 850mb
temps drop below -20C by 00z Friday. A non- diurnal temp trend
continues on Thurs with temps falling below zero summits to
single digits and teens valleys.

Key Message 3: Behind a departing longwave trough, strong caa with
continued breezy to gusty northwest flow aloft, will drop Thursday
night lows into the single digits above and below zero, and wind
chills into the negative single digits to negative teens. The
coldest locations will be across northern New York where additional
snow could enhance any radiative cooling effects with clearing
skies. Winds will continue to be on the breezy side through the day
Friday and into Friday night with winds becoming southerly and
gusting towards 20-25 MPH. Highs Friday will be slow to reach the
upper teens to low 20s during Friday afternoon. While winds will
continue to gust Friday night, southerly flow will help limit lower
temperatures with modest waa. Wind chills Friday night will dip into
the single digits to low teens.

Key Message 4: A large-scale upper level gyre will continue to eject
numerous shortwaves into the region this weekend through early next
week. A brief warmup is possible with southwesterly flow Saturday
with highs into the low to mid 30s. However, temperatures will once
again come crashing down Saturday night into Sunday as an un-phased
shortwave traverses northwest across the St. Lawrence Valley.
Temperatures with the onset of precipitation should remain all snow
for those who see any showers, mainly across the St. Lawrence
Valley. A secondary shortwave will ride along the elongated longwave
over the Great Lakes with additional snow shower chances Monday into
Monday night. Neither of these systems appear impactful with both
unphased to the established moisture corridor off the coast, and
marginal forcing. However, a few inches of some fluffy snow is
possible across mainly northern New York. Vermont will likely reside
in a dry slot between the marginal forcing of the shortwave and the
moisture corridor off the coast. Snow lovers in Vermont (outside of
the spine of the Greens, where some upslope showers are possible),
will be disappointed with this forecast for early next week. Showery
weather will continue well into mid to late next week.

&&

.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
Through 18Z Wednesday...Prevailing VFR conditions are expected
to continue at the majority of terminals through the next 24
hours. Lingering low mountain clouds will lead to bouncing
MVFR/VFR ceilings at SLK/MSS/MPV for the next 1-2 hours, before
lifting back towards VFR conditions. Winds will become
predominately southerly this afternoon with increasing gusts at
all sites. Gusts overnight will reach 20-30 knots at most sites,
with channeled flow perhaps increasing gusts towards 30-40 kts
at BTV. With these increasing gusts, winds aloft at 2000ft agl
will be 50-55kts leading to widespread LLWS at least from
22-06Z. Winds will remain southerly by 12Z, but will weaken
towards 18Z tomorrow. A weak shortwave late this
afternoon/evening will provide some lift for at least some light
precipitation, mainly at MSS/EFK/RUT/SLK, with PROB30s at
BTV/PBG/MPV. The main timing of sustained precipitation will be
00- 06Z, with some lingering shower chances until 09Z.
Precipitation will be a mix of rain at MSS and snow with mainly
snow at SLK/EFK overnight. Ceilings likely will reduce to MVFR
under any showers, particularly at MSS/SLK, and remain down
through the remainder of the TAF period.

VFR sites at 12Z tomorrow will trend towards MVFR ceilings by 18Z
with an approaching frontal system.

Outlook...

Wednesday Night: Mainly MVFR, with areas IFR possible. Likely SN,
Likely RA.
Thursday: Mainly VFR, with local IFR possible. Chance SHSN.
Thursday Night: VFR. Slight chance SHSN.
Friday: VFR. NO SIG WX.
Friday Night: Mainly VFR, with local MVFR possible. Chance SHSN.
Saturday: Mainly VFR, with areas MVFR possible. Chance SHSN.
Saturday Night: Mainly VFR, with local IFR possible. Chance SHSN.
Sunday:  Chance SHSN.

&&

.EQUIPMENT...
NOAA Weather Radio station WXM-44, transmitting from Mt.
Ascutney, Vermont, on frequency 162.475 MHz is non-operational
at this time. NWS technicians have diagnosed the problem, but
repairs will likely not be able to occur for quite some time due
to circumstances beyond our control. Therefore, the time of
return to service is currently unknown. The following NOAA
Weather Radio transmitters may be able to provide service during
this outage: WWG 50 from Burke Mtn, VT at 162.425 MHz and WNG
546 from Hanover, NH at 162.525 MHz.

The Colchester Reef meteorological station is out of service.
This site is not serviced by the NWS and there isn`t an
estimated return to service at present. Use extra caution when
navigating the broad waters of Lake Champlain. Please contact us
if you observe winds significantly deviating from the
recreational forecast.

&&

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

&&

$$

DISCUSSION KEY MESSAGES 1 and 2...Taber
DISCUSSION KEY MESSAGES 3 and 4...Danzig
AVIATION...Danzig
EQUIPMENT...NWS BTV