327
FXUS61 KBTV 210711
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
211 AM EST Wed Jan 21 2026
.WHAT HAS CHANGED...
As of 121 AM EST Wednesday...No significant changes were made to
the forecast.
&&
.KEY MESSAGES...
As of 121 AM EST Wednesday...
1. Light to localized moderate snowfall associated with rounds
of snow showers with possible snow squalls, primarily late
Wednesday into Thursday and again on Friday, will produce some
hazardous travel.
2. A significant and dangerously cold arctic outbreak is
expected late week into the upcoming weekend with wind chill
values 20 to 40 degrees below zero likely.
&&
.DISCUSSION...
As of 121 AM EST Wednesday...
.KEY MESSAGE 1: A series of fronts, including a warm front
tomorrow evening, a cold front on Thursday, and an Arctic
boundary on Friday, will support snow showers through the rest
of the week.
Nighttime satellite depicts a narrow corridor of enhanced
relative humidity associated with an intense lake effect snow
band that has drifted northward off the Tug Hill plateau into
the northern Adirondacks and the northern Champlain Valley. The
band is oriented along the fetch of Lake Ontario, allowing for a
fairly elongated area of instability protruding into northern
Vermont, supporting light snow showers. This band is expected to
continue drifting north and westward over the course of the this
morning, returning to the southern portions of St. Lawrence
County by daybreak. As the band shifts northwestward, the fetch
axis will weaken the moisture of the band retracting any
lingering snow showers away from Vermont and back into the
northern Adirondacks. Outside of the LE, the next round of light
snowfall will arrive with a quick moving clipper system late
this afternoon with more widespread snow chances from stronger
850mb warm air advection. A warm front will lift through the
region this afternoon with some warm advection snow showers
mainly across northern New York, though a quick dusting to an
inch of snow is possible in the higher terrain of Vermont.
Snowfall rates are only likely to be up to 0.5"/hour in general,
with the best chance for any 1"/hour rates and impacts to the
Wednesday evening commute, in northern New York especially in
the western and southern areas. Behind the warm front Wednesday
evening into Wednesday night, south winds will become gusty up
to 30 to 40 MPH in the Champlain Valley from channeled flow, and
along the northern periphery of the northern Adirondacks from
some downsloping. Its possible some locations may experience a
brief period of locally higher gusts in the Champlain Valley
with a low level jet around 50-55kts, however, synoptic dynamics
do not support widespread or prolonged impactful gusty winds at
this time. The development of these strong winds will likely
shred any dendrites in the Champlain Valley and eastern
Adirondacks Wednesday night with a dry slot and narrower
dendritic growth zone, supporting limited snowfall. Total
snowfall through Wednesday night favors a dusting to an inch
for most of Vermont, with 1 to 3" across northern New York, with
the higher totals in the southwestern St. Lawrence Valley.
Winds will gradually shift to the southwest by Thursday morning
ahead of a strong arctic front and resurging LE. Lapse rates
will steepen with good vertical mixing with height falls,
leading to CAPE values up to 120J/kg. This forcing however, will
be relatively broken and in waves with no real convergence with
primarily southwest winds in the entire column, supporting
disorganized areas of snow showers, some of which may contain
embedded snow squalls. It is difficult to pinpoint the exact
timing and location of these snow showers and squalls due to
the presence of a strong southwesterly jet and a lack of a true
convergent boundary. However, generally southwest flow favors a
shadowing setup for the Champlain Valley downwind of the
Adirondack High Peaks. Away from the CPV, snow squalls may cause
localized hazardous travel for the Thursday evening commute. Outside
of the squalls potential, a resurging intense LE band from Lake
Ontario will redevelop Thursday which will waffle along the St.
Lawrence/Lewis/Herkimer County New York border. Current
forecasts have trended towards the potential for a Winter
Weather Advisory for southeastern St. Lawrence County with snow
totals between 2-4". However, there is still some uncertainty
with where the band sets up which will greatly dictate the snow
totals for the area. Regardless, the band is modeled to contain
period of potentially 1-2"/hour rates per the HREF. If trends
continue with the 12 and perhaps 18Z model runs, Winter Weather
Advisories may be issued as early as this afternoon for the
aforementioned areas. Any snow squalls and lake effect showers
will diminish and shift south, respectively, as a strong arctic
cold front drops into the region Friday. Additional snow showers
will be possible as the boundary shifts south, but the main
impact will be the dangerous cold proceeding the boundary for
the weekend.
.KEY MESSAGE 2: We continue to see strong signals in model
guidance and patterns for a significant and dangerous arctic
outbreak late this week and over the weekend. Extreme Cold
Warnings and Cold Weather Advisories will be needed for the
forecast area late Friday into Sunday. Temperatures during this
period as low as -5 to -25 F and brisk northwesterly flow
transitioning to high pressure/radiational cooling will likely
result in wind chills -20 to -40 F. Strong cold air advection in
northwesterly flow is expected Friday evening into Saturday
morning with wind gusts as high as 20-30 knots likely in
valleys, and higher possible on the summits. These winds,
combined with intensely cold air flowing into the region (850mb
temps as low as -29 to -32 C) are expected to produce frigid
surface wind chills in 20 to 40 below zero degrees Fahrenheit.
Saturday, the bitterly cold air aloft will begin to retreat,
and northwesterly winds will also begin to decrease as high
pressure noses into the region. We will even have some periods
of sunshine throughout the day, however, wind chills are likely
to not reach above zero degrees at all, with many spots seeing
maximum wind chills 10 to 30 degrees below zero. Saturday night,
we`ll see high pressure take hold of the region and result in
optimal radiational cooling conditions as winds become light and
variable. While winds will be less of a factor during this
period, and increasing clouds associated with a coastal low
pressure system may limit radiational cooling later on in the
night, wind chills are still expected to be in the 0 to -30 F
range Saturday night into the Sunday morning hours.&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Through 06Z Thursday...Several rounds of snow showers,
including locally heavier snow, will occur early this morning
through Friday. These showers will be associated first with a
lake effect snow band stretched across northern New York and
northern Vermont this morning, then with a series of frontal
boundaries later today (Wednesday) through the end of the week.
Gusty winds and possibly snow squalls this upcoming night
(Wednesday night) could lead to localized blowing snow, creating
hazardous travel conditions. Current sites under the lake
effect snow band off Lake Ontario include SLK and BTV, which are
both reporting ceilings around 1000- 3000 feet. Snow is
heaviest at SLK with visibilities 1-2 miles, but as the moisture
thins out farther from Lake Ontario, snow has been lighter at
BTV, generally 5+ miles. High resolution models are all
indicating the band will shift north and west as the early
morning progresses, potentially bringing some light snow and
perhaps some isolated MVFR cigs to PBG and then MSS as well.
Winds out of the southwest are decreasing early this morning
with some sites going calm or light and variable, but we should
see another slight increase in winds and a turn out of the
south- southwest around 09Z-12Z. Lake effect snow will come to
an end by around 12Z Wednesday, but by 18Z Wednesday, we should
already start to see snow returning to parts of northern New
York ahead of a warm frontal boundary, and this snow will
progress across the entire forecast area during the rest of the
afternoon and evening. We`ll also see winds picking up even more
out of the south around or shortly after this time with gusts
15-35 knots for most sites through 06Z Thursday. Winds look to
be strongest in the Champlain Valley (BTV and PBG) due to the
north-south orientation of this wider valley. Snow is expected
to come to an end around 00Z-04Z Thursday for some, but some
showers could linger through 06Z Thursday. MFR ceilings are
anticipated to accompany the showers from 20Z-23Z Wednesday
onwards. Low level wind shear is expected to be widespread
around 21Z Wednesday through 06Z Thursday as a strong
southwesterly low level jet increases overhead while surface
winds remain more southerly.
Outlook...
Thursday: Mainly VFR, with local MVFR possible. Chance SHSN.
Thursday Night: VFR. Slight chance SHSN.
Friday: VFR. Chance SHSN.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. Slight chance SN.
&&
.CLIMATE...
Record low maximum temperatures are possible on Saturday; below
are the current records:
KBTV (Burlington area): -4 in 1907
KPBG (Plattsburgh area): 0 in 1976
KSLK (Saranac Lake area): -10 in 1936
KMSS (Massena): -5 in 2004
KMPV (Montpelier): 0 in 2004
SJBV1 (St. Johnsbury): -3 in 1907
&&
.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...Danzig/Storm
AVIATION...Storm
CLIMATE...NWS BTV
EQUIPMENT...NWS BTV
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