Williston, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

455
FXUS61 KBTV 251318
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
818 AM EST Thu Dec 25 2025

.SYNOPSIS...
Snow showers are starting to move into the area this morning.
The terrain driven nature of this system will lead to
accumulations of several inches in the northern Greens and
Adirondacks. Friday will be sharply colder following a frontal
passage, min temperatures will fall into the single digits above
and below zero in the morning. The next impactful system will
arrive on Monday with the potential for mixed precipitation.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 809 AM EST Thursday...Issued a quick update this morning,
mainly to freshen up PoPs and weather to match the latest radar
trends. The steadiest snow is pushing southward through northern
VT and NY at this hour, associated with a cold frontal boundary
moving out of Canada. Snow will taper to scattered showers from
north to south as this feature moves through. Winds will turn to
the N/NW and become gusty behind the front as well, which may
lead to areas of blowing snow. Snow accumulation will be light,
mainly less than 2 inches, though more is expected on the higher
summits. Even a bit of snow accumulation can make for slippery
roads, so please use caution if you`ll be out and about today.

Previous discussion...Radar shows snow approaching northern New
York and Vermont from the north. The primary push of snow
should be through the area by 15z, bringing an inch or two to
many locations. CAMS are suggesting some the northern Greens
might hold on to some orographic snow through the early
afternoon hours. We could also see some light lake enhanced snow
this afternoon and into the overnight hours south of Lake
Champlain. Following the snow, an arctic cold front will sweep
into the area dropping temperatures below zero for much of our
forecast area. Southern Vermont will be the warmest location in
our forecast area but is still showing a 20% chance of falling
below zero.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 205 AM EST Thursday...The arctic air will remain in place
during the day Friday, with temperatures only warming into the teens
for most locations, with single digits remaining in colder and
higher elevation areas. Friday night into Saturday a low pressure
system will dive south of our CWA. Model guidance has routinely
showed this system delivering a glancing blow to us, with some light
snowfall in southern Vermont and the Southern Adirondacks, with the
rest of our area only seeing some flurries. The NAM3 is now
diverging from that consensus, with a low passage far enough north
tn on to bring more substantial snowfall to Vermont and northern New
York. We will continue to monitor the high res models as they hone
in on this system.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 205 AM EST Thursday...We remain on track to see a classic setup
for transient, freezing rain as an intensifying low pressure system
tracks to our west with a retreating, cool high pressure system to
our east. While we maintained mention of snow with some inherent
precipitation type questions in this time range (eg. some global
ensemble members suggest snow is possible), there really is a strong
consensus of mainly freezing rain/rain scenario Sunday night into
Monday until the low pressure system passes to our northeast and
winds shift westerly. Expect Winter Weather Advisories could be
needed areawide for Sunday night/early Monday with at least light
freezing rain given cold surface conditions and only a light
925/surface south to southeast wind through this period. Preliminary
thoughts for ice amounts in the range of 0.1" to 0.25" of flat ice,
and locally 0.5", seems reasonable for most of the region at this
time, with maybe a trace of ice in some areas that warm above
freezing relatively quickly in these scenario with southeasterly low
level wind, such as in southeastern St. Lawrence County.

The other potential hazards with this event would be related to
gusty winds and falling temperatures on the backside of the storm.
The ECMWF Extreme Forecast Index supports noteworthy, if not
particularly unusual, westerly wind gusts later Monday into Tuesday.
As we get closer to this period we`ll also target lake-
effect/terrain-driven heavier snow potential, and generally fine-
tune coverage of snow showers. Broad cyclonic flow and seasonably
cold air will set up multiple opportunities for snow in our region
on Tuesday and Wednesday.

&&

.AVIATION /13Z THURSDAY THROUGH MONDAY/...
Through 12Z Friday...It remains a somewhat difficult forecast
for northern portions of the airspace with regards to
operational impacts early in the period ahead of an approaching
cold front. Following a brief respite of steady snow, another
batch of snow near the International Border at 12Z, on the
leading edge of the front, will move southward bringing at least
temporary IFR conditions to most terminals through 15Z. Aside
from the snow, MVFR conditions are expected through the rest of
the period driven by ceilings. A shallow, post-frontal stratus
layer is expected for much of the period, with scattering first
at MSS and much later at other sites, based on model guidance
and upstream observations with cloud bases mainly in the
1000-2000 foot range.

Light south/southwest winds are currently in place, as well as
probable wind shear conditions at MPV/SLK/EFK/RUT. As the cold
front passes we will see primarily northwest winds of 5-10 knots
by 16Z with lack of LLWS. Winds will become gusty with 20-25
knots common, only diminishing slightly at most sites after 06Z.


Outlook...

Friday: VFR. NO SIG WX.
Friday Night: VFR. Chance SN.
Saturday: VFR. Slight chance SN.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. Chance SN, Slight chance FZRA.
Sunday Night: Mainly VFR, with local MVFR possible. Definite PL,
Chance FZRA, Chance SN.
Monday: Mainly IFR, with areas MVFR possible. Windy with gusts to
30 kt. Definite SN, Definite RA, Definite FZRA, Definite PL.

&&

.MARINE...
Behind a cold front, increasingly deep mixing of colder air will
result in a long duration of strong northwest winds across the
lake with 20-25 knot winds and gusts to 30 knots common late
this morning and into the night. Maximum wave height of 3 to 6
feet over the broad waters and 2 to 4 feet in on the inland sea
can be expected.

&&

.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.

&&

$$
SYNOPSIS...Langbauer
NEAR TERM...Hastings/Langbauer
SHORT TERM...Langbauer
LONG TERM...Kutikoff
AVIATION...Kutikoff
MARINE...Kutikoff
EQUIPMENT...Team BTV