570
FXUS61 KBTV 091859
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
159 PM EST Tue Dec 9 2025
.SYNOPSIS...
Widespread snowfall will move through tomorrow into tomorrow
night, with accumulations generally expected to be in the two to
seven inch range. Plan on slippery road conditions, particularly
during the Wednesday morning and evening commutes, as well as
between 10 AM and 3 PM Wednesday, when heavy snow is
anticipated. The colder and active pattern will continue into
next week with a few additional chances for snow, though no big
snowstorms are expected.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
As of 145 PM EST Tuesday...
**Winter Weather Advisories have been issued for St. Lawrence,
Franklin, and western Essex counties of New York as well as
Rutland, Washington, Orange, Caledonia, Lamoille, Essex,
eastern Addison, and western Windsor counties of Vermont.
**In New York, the Advisory runs from 7 AM Wednesday through 7
AM Thursday, while in Vermont, the Advisory runs from 7 AM
Wednesday through 1 AM Thursday.
**Plan on slippery road conditions, particularly during the
Wednesday morning and evening commutes, as well as between 10
AM and 3 PM Wednesday, when heavy snow is anticipated.
High pressure centered over southern New England will shift off into
the Atlantic Ocean this afternoon and evening as low pressure
approaches northern New York from the Great Lakes. This will enhance
warm air advection across the forecast area and commence a period of
light snow showers. Dry air at the surface will make it difficult
for snow to reach the ground, so any snow accumulations will
generally be only a couple tenths of an inch throughout the night,
though higher elevations in the Adirondacks and northern Greens
could pick up an inch or two. This warm air advection will also keep
lows milder than we saw last night, though still a few degrees below
seasonal normals in the teens to lower 20s. A southwesterly low
level jet with winds 40-45 knots will accompany the warm air
advection, bringing gusty winds on mountaintops and ridges and
efficient atmospheric mixing will also produce gusts up to 30-35
knots at the lower elevations, highest in north to south oriented
valleys like the Champlain Valley due to efficient channeling. Any
new snow will likely be light and fluffy and blow around easily,
lowering visibilities.
Tomorrow, a quick-moving clipper type system will cross the region,
its surface low tracking through the St. Lawrence Valley tomorrow
afternoon into the overnight period. Snow will be steadiest
throughout the daytime hours tomorrow with warm air advection in the
morning enhancing snowfall intensity and higher snow ratios on the
front end allowing snow to pile up quickly. Snowfall rates in the
morning could briefly reach around an inch per hour, then turn
lighter in the afternoon. Downsloping and shadowing will overall
limit snowfall in the Champlain and Connecticut River valleys. We`ll
also continue to see southerly to even southeasterly gusts tomorrow
up to 25-30 knots, again strongest in north to south oriented
valleys.
Warm air advection and southerly flow will help make tomorrow the
mildest day of the week with highs in the upper 20s to mid 30s, near
seasonable for this time of year. In locations like the wider
valleys where we`ll have temperatures rising slightly above freezing
in the late afternoon, we could see some rain mixing in briefly, but
generally steep lapse rates will keep snow the dominant
precipitation type for this entire event. As the center of the low
passes to the east, northwest flow develops and it should cause a
brief period of upslope snow Wednesday night with lows in the single
digits to lower 20s. Overall, totals in the three to seven inch
range are generally expected in areas we`ve issued a Winter Weather
Advisory and up to three or four inches possible elsewhere. The lake
effect band should stay to the south of our northern New York zones,
though the moisture will still enhance totals in the central and
southern Greens.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 145 PM EST Tuesday...Upslope snow showers are expected Thursday
and Thursday night as temperatures dive back down in cold air
advection following the system discussed in the near term
discussion. Gusty winds will continue out of the west and southwest
during this period as well. Highest snow accumulations will be
focused across the northwestern Adirondacks and the northern Greens
with up to 3 to 6 inches possible. In the southern wider valleys and
eastern slopes, we`ll see minimal to no snow with even some clearing
possible late Thursday night. Temperatures Thursday will be in the
teens and 20s during the day, falling to the single digits and teens
Thursday night.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 159 PM EST Tuesday...Below normal temperatures will continue
throughout this period, as a persistent ridge along the west coast
helps maintain a clipper-type of storm track along with surges of
Arctic air. Greatest chances for extreme cold continue to be in the
late Sunday to Monday timeframe, with the coldest guidance from both
machine learning and traditional computer models showing a lobe of
850 millibar temperatures in the -22 to -25 C range dropping
southeastward into the area early Monday. As a result of the cold
and northwesterly winds, when current minimum wind chills are
forecast mostly in the -5 to -15 F range but could trend lower.
Progged 850 millibar temperatures will remain mainly below the 20th
percentile relative to climatology, with slight moderation on
Saturday before dropping below the 10th percentile, and perhaps 5th
percentile on Monday.
Have noted there is more spread early next week, with some global
ensembles favoring extreme cold and others actually moderating
temperatures slightly during the same timeframe. These differences
seem to be tied to how a lobe of the polar vortex, which will track
southeastward towards us, interacts with any coastal low pressure
storm that develops over the weekend. Only in situations with a
deeper low that curls northward rather than pushing eastward do we
see the most intense cold.
Noticed as winds slacken Friday evening with weak ridging sliding
across the area ahead of the next clipper system, we might be
dealing with a frigid night with good radiational cooling,
especially east of the Green Mountains. Would expect forecasts to
trend sub-zero for overnight low temperatures.
With regards to snow chances, the aforementioned coastal low
pressure system would be our opportunity for a more impactful
snowfall, but chances this develops in a way to bring our region
heavy snow is low (under 20%). The primary low pressure area will
probably pass to our northwest on Saturday and weaken as the
secondary low develops to our southeast, with a lot of westerly flow
limiting PoPs in eastern Vermont while snow showers will be common
in much of the remainder of the region. Until the long wave trough
axis pushes to our east, chances for upslope snow showers and
potentially more organized light snow will continue into early next
week.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
Through 18Z Wednesday...It is a quiet forecast over the next six
hours with a layer of altostratus present ahead of a warm front,
then active conditions including LLWS and snow will follow. Bulk of
steady snow will be between 12Z and 18Z, with visibilities likely
as low as 1/2SM at most sites towards the end of the period.
Character of snow initially will be dry and very light with the
first showers that arrive in the 00Z-12Z period. In fact, at PBG and
BTV, precipitation may be virga with little or no operational
impact. Widespread snow then arrives towards 12Z and become
much heavier, trending wet, especially at KRUT where snow to
liquid ratios could be near 10:1. Other sites will see snowfall
with mainly moderate snow to liquid ratios closer to 12:1.
Flight conditions will be driven by visibilities, as ceilings
lower to mainly 2 to 5 thousand feet outside of the steady snow.
Southwesterly winds aloft will greatly increase tonight,
leading to LLWS as surface winds remain southerly and relatively
light (around 10 knots). Greatest risk of LLWS is at RUT, MPV,
and SLK and during the predawn hours. After a lull, LLWS will
return towards the end of the TAF period. Other sites will tend
to see turbulence but less shear, with wind gusts as high as 25
knots at BTV, especially prior to 12Z and arrival of snow.
Outlook...
Wednesday Night: MVFR/IFR conditions possible. Chance SHSN.
Thursday: Mainly VFR, with local MVFR possible. Chance SHSN.
Thursday Night: VFR. Slight chance SN.
Friday: VFR. NO SIG WX.
Friday Night: Mainly VFR, with local MVFR possible. Slight chance
SN.
Saturday: Mainly VFR, with local MVFR possible. Chance SN.
Saturday Night: Mainly MVFR, with local IFR possible. Chance SN.
Sunday: Mainly VFR, with local IFR possible. Chance SN.
&&
.MARINE...
We have issued a Lake Wind Advisory for the Broad Waters of Lake
Champlain as south winds 15 to 25 knots are anticipated this
afternoon. Waves will be 1 to 3 feet this afternoon, building 3
to 5 feet this evening. We anticipate the need for an expansion
of the Lake Wind Advisory to all other zones of the lake this
evening with south winds 15 to 30 knots and gusts as high as
30-40 knots possible.
&&
.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.
Equipment malfunctions at the Colchester Reef meteorological
station will likely leave it inoperable for an extended period
of time. This site is not serviced by the NWS. Technicians do
not currently have an estimated return to service for this
station. Use extra caution when navigating the broad waters of
Lake Champlain, and please contact us if you observe winds
significantly deviating from the forecast.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Winter Weather Advisory from 7 AM Wednesday to 1 AM EST
Thursday for VTZ004-006>008-010-011-017>020.
NY...Winter Weather Advisory from 7 AM Wednesday to 7 AM EST
Thursday for NYZ026-027-029-030-034-087.
&&
$$
SYNOPSIS...Storm
NEAR TERM...Storm
SHORT TERM...Storm
LONG TERM...Kutikoff
AVIATION...Kutikoff
MARINE...Storm
EQUIPMENT...Team BTV
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