337
FXUS61 KBTV 200643
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
143 AM EST Tue Jan 20 2026
.WHAT HAS CHANGED...
As of 140 AM EST Tuesday...The Winter Weather Advisory has been
cancelled as the lake effect snow band has drifted south of the
region.
&&
.KEY MESSAGES...
As of 140 AM EST Tuesday...
1. Lake effect snow shower chances will diminish this morning, but
return this afternoon with continued cold conditions tonight.
2. Continued chances for light to moderate snow chances with
possible embedded snow squalls and gusty winds Wednesday into
Thursday as temperatures briefly increase back to seasonable
norms.
3. 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 possible.
&&
.DISCUSSION...
As of 140 AM EST Tuesday...
.KEY MESSAGE 1: Chances for snow showers continue into mid week
with a series of cold fronts associated with deepening low
pressure systems traversing the region. Winds will become more
westerly this morning into the afternoon which will help keep
the lake effect band off Lake Ontario to our south for most of
the day today. However, winds will once again turn southwesterly
by late this evening pushing the lake effect band north back
into the southern St. Lawrence County. Winds aloft will slacken
today and this evening outside of the higher terrain lessening
the northeast extent of the lake effect band. However, some
isolated to scattered chances for snow showers enhanced by the
lake can be expected downwind of the band in the Adirondacks and
along the spine of the central and northern Greens this
afternoon. Steep lapse rates and instability should be able to
sustain at least some snowfall in the higher terrain. With
limited coverage of the snow today, widespread travel concerns
do not look likely, however, by Wednesday, a secondary system
will bring more widespread chances of snow and gusty winds.
Temperatures today and tonight will remain on the cold side
with highs remaining in the teens and overnight lows into the
single digits.
.KEY MESSAGE 2: Another deepening low pressure well north of us
will drag along a warm front followed by a cold front with
continued southwest flow Wednesday night into Thursday.
Increased moisture with enhanced synoptic forcing will allow
widespread warm advection snow showers to overspread northern
New York and perhaps some snow showers along and east of the
Greens in Vermont Wednesday night. The best forcing and moisture
convergence will be over the St. Lawrence Valley, however,
steepening lapse rates and orographic lift should be able to
sustain some shower activity across the higher terrain of
Vermont. Southwesterly flow aloft likely will limit the shower
activity in the Champlain Valley. A dusting to an inch or two
can be expected mainly across the Adirondacks and the St.
Lawrence Valley. The main impact for Wednesday night will be
increasing southerly surface winds in the Champlain Valley and
the northern Adirondacks. South flow up to 30 to 40 mph will be
channeled up the Champlain Valley Wednesday night into Thursday
morning and along the northern periphery of the Adirondacks.
These winds in areas of snow showers could lead to blowing snow
with localized hazardous travel concerns. Southerly surface flow
will also lead to non-diurnal temperatures Wednesday night with
temperatures increasing overnight into the upper 20s to low
30s. Behind the warm front, southwest winds will enhance a
reinvigorated lake effect band off Lake Ontario Thursday. A
strong arctic cold will lead to enhanced forcing with localized
heavy snow showers along with the lake effect snow showers
Thursday afternoon. Instability will be near 100 J/kg, however,
the convergence will limit the overall linearity of any squalls
that develop. The NAM12 depicts snow squall parameter values 2
to 5. Snow showers will likely come in disorganized waves,
however, these waves will be scattered to numerous.
KEY MESSAGE 3: A significant and dangerous arctic outbreak is
looking more an more likely late week into the weekend as an
extremely cold airmass moves into the region. Strong cold air
advection is expected to occur across the forecast area on
Friday and Friday night, then very cold 850mb temperatures -29
to -33 C crest over the forecast area late Friday night and
early Saturday morning. Surface temperatures look to fall into
the -20 to 0 F range during this period with wind chills as low
as -10 to -35 F, even colder on mountaintops. Based on what
we`re seeing now, we`ll likely need Cold Weather Advisories in
place for most of the forecast area with potentially an Extreme
Cold Warning for parts of northern New York where wind chills
may be coldest.
Saturday will remain cold with highs only in the single digits
above and below zero and high pressure taking hold of the
region. Northwesterly surface flow is expected to continue
throughout the day, making for MAXIMUM wind chills in the -15 to
5 F range, though most of the day should have wind chills
around 5 below zero or lower. As is typical with high pressure,
we anticipate light winds and breaks of clear sky throughout
Saturday night, which would mean another very cold night with
lows in the -20 to -5 F range. Wind chills Saturday night,
though not quite as low as Friday night due to the calmer winds,
will fall into the -30 to 0 F range. There remains some
uncertainty on the longevity of the cold air as models show a
storm system off the southeastern U.S. coast that may bring some
milder air north into the forecast area late Saturday night and
early Sunday morning. Overall, temperatures look to moderate
into early next week but remain below seasonal averages.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...A lake effect snow band is shifting eastward
across northern New York and northern Vermont early this morning,
resulting in areas of very low visibility that will cause hazardous
travel conditions.
Current TAF sites affected by this lake effect snow are SLK and EFK.
SLK is much closer to Lake Ontario, the origin of the LE snow, so
its ceilings 800-1200 feet above ground level and visibilities 1/2
to 3 miles have both been much more persistent over the last few
hours. For EFK, IFR conditions are much more off and on with
ceilings between 600 and 7000 feet and ceilings as low as 1/2 mile
but often more than 6 miles.
We anticipate prevailing IFR conditions will
linger at SLK through around 07Z-09Z Tuesday, then we`ll see
ceilings improve with on and off lingering IFR showers. At EFK, it`s
tougher to say, but thinking snow showers may continue on and off
over the next few hours, bringing with them lowered vis and cigs.
Otherwise, mainly VFR conditions out there early this morning with
VFR at all sites expected by 09Z-15Z Tuesday and continuing through
06Z Wednesday.
Brisk southerly and southwesterly winds 5-15 knots with gusts 15-25
knots early this morning will continue for most of the next 24
hours, blowing snow around and reducing visibilities. We`ll likely
see a drop in gusts at most sites around 20Z-23Z Tuesday, still
leaving sustained winds 5-15 knots into Wednesday. Some brief and
localized LLWS is possible at SLK around 00Z-06Z Wednesday as
westerly winds increase aloft.
Outlook...
Wednesday: Mainly VFR, with local MVFR possible. Windy with gusts
to 30 kt. Chance SHSN.
Wednesday Night: Mainly VFR, with local MVFR possible. Windy with
gusts to 30 kt. Chance SHSN.
Thursday: VFR. Chance SHSN.
Thursday Night: VFR. Slight chance SN.
Friday: VFR. Slight chance SN.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
&&
.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
EQUIPMENT...NWS BTV
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