222
FXUS61 KBTV 311847
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
147 PM EST Wed Dec 31 2025
.SYNOPSIS...
Widespread snow arrives this evening and tonight, with most areas
seeing 1 to 4 inches of snow by daybreak tomorrow, and 4 to 9
inches expected in the St. Lawrence Valley. Seasonably cold
weather continues into the New Year along with occasional
chances for mountain and lake effect snow showers. Moderating
temperatures are expected for the middle of next week ahead of
another weather system.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 114 PM EST Wednesday...Winter Weather Advisories remain in
effect, and for southwestern St. Lawrence County, the Winter Weather
Advisory has been upgraded to a Winter Storm Warning - in effect
through 7 AM/12Z.
Rapid refresh guidance and 12z high res guidance have trended
towards more intense lake effect snow, especially across
southwestern St. Lawrence County. Based on observations downwind of
Lake Ontario, heavy snowfall rates of 1-2"/hr of snowfall appears
likely along Gouverneur with the highest potential between about 5
PM and midnight. Given that breadth of time, reaching 7" should meet
the 80% confidence bar for the warning. Lake effect snow will lift
ahead of an approaching surface low. Deepening is expected as the
500mb upper low trends close to 500 dam, and an upper jet streak
will nose in south of the region, placing northern New York very
favorably within the left exit region of that jet. Sharp convergence
along the surface low abutting the northwestern slopes of the
Adirondacks will make that region most favored for snow as the low
tracks overhead, which makes this event a bit of a hybrid case for
St. Lawrence County.
Across Vermont, residual dry air and 850mb flow increasing to 30 to
40 knots will result in an initial drop of snow this evening that
lifts north, followed by terrain shadowing. As the surface low
tracks overhead overnight and northwest flow initiates, we`ll see
snow fill back in and then become terrain favored, leading to
amounts mainly between 1-4", with locally lower patches in southern
Vermont and on the New York side of the Champlain Valley.
One potential inhibiting factor will be how cold the air is. As the
surface low shifts east, we cool below the dendritic growth zone. So
we should go from a 20-25:1 SLR to something closer to 15:1 on
the backside. Winds are expected to slacken as the surface low
approaches. So squalls are not anticipated. However, on the
backside, northwest flow will quickly allow for gusts 20-25 mph,
locally up to 35 mph. So blowing/drifting snow is likely,
especially with icy surfaces being a smooth frictionless surface
and this snow leaning on the powdery side. This will probably
also make measuring a little challenging too.
The main concern will be for holiday celebrations. The combination
of blowing snow and locally heavy snow in parts of the St. Lawrence
County may catch motorists off-guard with poor visibility within the
moving target of heaviest snow. The initial lake effect band will be
fairly transient, and will then merge with potential mesoscale
banding on the northwest side of the strengthening surface low then
sliding east. So for northern New York, be prepared for changeable
weather, especially as wind chills fall towards -5 to -15 F.
Temperatures have managed to warm nicely ahead of the surface low in
the teens and mid 20s, but on the backside of the low, temperatures
will quickly fall into the upper single digits to lower 10s across
Vermont and near 0 over northern New York. Snow will taper off New
Year`s Day with continued chilly weather within northwest flow.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 114 PM EST Wednesday...Cold weather will continue Thursday
night into Friday. Temperatures on Friday morning will be very
chilly, with low temperatures near 0 to the single digits below
zero. Winds will abate, though. So radiational cooling will at least
have minimal wind chills. We don`t moderate much on Friday with
mainly 10s to near 20. A subtle trough will angle southeast late
Friday into the overnight hours. This should lure some lake effect
snow to our south northwards, and could also have a few showers of
its own along the international border. At this time, amounts appear
likely to be on the lighter side. Another cold night will pass
Friday night into Saturday, with single digits to near 0 again.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 114 PM EST Wednesday...Cold and dry conditions are expected for
the most part on Saturday, with high temperatures well below normal,
mainly in the teens. Some very light, isolated snow showers are
possible (under 20% chance), especially in the Northeast Kingdom and
mountains.
More interesting weather may follow Saturday night into Sunday, and
again Monday afternoon - Monday night with more widespread light
snow events in northwest flow. While it is likely to snow at some
point through this period, the specific timeframe cannot be known in
this pattern, so note precipitation chances currently are shown in
six hour windows in the range of 10-40%. Signals for below normal
temperatures are strong through Monday, then weaken Tuesday into
Wednesday when there is some spread in the 500 millibar height
fields after a long period of persistent troughing. Generally the
cold will likely ease by midweek, although the degree of warming is
unclear. Breaking it down by the most recent ensemble clusters, one
multi-model cluster, especially in the GEPS, shows 850 millibar
temperatures becoming above normal, while the mean in other clusters
primarily from the GFS and ECMWF ensemble show near normal values.
So at this time, near normal temperatures currently forecast (highs
in the upper 20s to low 30s) is reasonable with the possibility for
warmer conditions/thawing, with further warming possible for
Wednesday.
At this time, a significant low pressure system is unlikely as the
upper air pattern trends zonal midweek, but with some kind of
frontal system approaching from the west we`ll be monitoring for
somewhat heavier precipitation with possibility of a rain/snow mix
in the valleys. Stay tuned!
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Friday...An area of light snow is gradually blossoming
over the airspace, a little faster than originally expected. With
dry air in place, most precipitation will be flurries except at
higher elevations such as at SLK where visibilities have already
dropped under 3SM. Low chances of IFR conditions through 00Z
elsewhere, although it would not be surprising if snow briefly was
sufficiently heavy to do so at any site. After 00Z chances for
steadier snow increase with the approach of a low pressure system
from near Lake Ontario. As the low moves northeastward just east of
MSS around 09Z and passing just north of BTV and EFK through 12Z,
some snow showers are likely at most sites before dry air scatters
out the cloud cover, with perhaps brief MVFR flight conditions
trending VFR, in the wake of the front.
Currently winds are mainly westerly, with some gusts near 20 knots
at most sites with steep low level lapse rates but winds aloft are
not quite to the level to be concerned with LLWS. These winds will
trend southerly, favoring BTV with regards to gusts while turning
northeasterly at MSS, between about 00Z and 04Z. These conditions
will continue until the aforementioned low pressure system and
attendant front pass, with a sharp wind shift to northwesterly
or westerly between 10Z and 14Z. Peak gusts will likely be 20-30
knots for a short time, then decrease gradually through the
remainder of the period.
Outlook...
Thursday Night: VFR. NO SIG WX.
Friday: VFR. Slight chance SHSN.
Friday Night: VFR. Slight chance SHSN.
Saturday: Mainly VFR, with local MVFR possible. NO SIG WX.
Saturday Night: Mainly VFR, with local MVFR possible. Slight
chance SHSN.
Sunday: Mainly VFR, with areas MVFR possible. NO SIG WX.
Sunday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Monday: VFR. 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.
The Newport AWOS has stopped reporting due to a communications
failure likely at the site. TAF amendments will not be
scheduled until this issue is resolved.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...Winter Weather Advisory until 7 AM EST Thursday for NYZ026-027-
029-030.
Winter Storm Warning until 7 AM EST Thursday for NYZ087.
&&
$$
SYNOPSIS...Haynes
NEAR TERM...Haynes
SHORT TERM...Haynes
LONG TERM...Kutikoff
AVIATION...Kutikoff
EQUIPMENT...Team BTV
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