597
FXUS61 KBTV 011820
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
120 PM EST Mon Dec 1 2025
.SYNOPSIS...
More snow showers are moving through this morning with minor
accumulations possible through sunrise. Focus continues to
remain on two systems expected to impact the region Tuesday and
Thursday. Tuesday`s system will bring widespread snow
accumulations with potential for heavy snowfall mainly across
portions of southern Vermont. The Thursday system could bring
squall-like showers followed by a blast of cold air that will
decrease temperatures well below seasonal averages Thursday
night into Friday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 128 AM EST Monday...A front is moving through the region
this morning bringing snow showers with minor snow accumulations
generally less than 1 inch except southeast of Highway 11 in
southeastern St Lawrence and north-central Franklin counties of
New York where up to 2 inches are possible. Radar shows snow
showers over northern New York progressing eastward towards
Vermont. Models project this area of showers to break down as it
tracks eastward, but if it holds together (about a 25% chance),
timing could place showers in the Champlain Valley for the
morning commute possibly causing some visibility issues and
minor traffic disruptions.
Otherwise, a blustery day is ahead behind this front with ample
cold air advection depressing temperatures to around 10 degrees
below seasonal averages. Highs will generally be in the 20s for
most locations except for southern Vermont which will likely
reach the low 30s before the front moves through. Heights and
pressure rise this afternoon through the early overnight hours
with fast moving migratory high pressure passing through.
Temperatures will cool into the teens for most spots with
single digits for portions of the Adirondacks and northeastern
Vermont. Clouds will be increasing sharply late as the next
system moves into the region.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 128 AM EST Monday...
* A Winter Storm Watch is in effect for central and southern
portions of Vermont from Tuesday morning through late Tuesday
night where some locations could exceed 7 inches of snowfall.
* Widespread 2-4 inches are expected elsewhere with 1-3 for
much of northern New York.
* Impacts to the morning and evening commute are anticipated.
Snowfall will spread northward Tuesday morning as low pressure
moves out of the mid Atlantic region to just off the New England
coast. Not much has changed in terms of the forecast track of
the low and position of the 925/850mb 0C lines which will remain
south of Vermont keeping precipitation character all snow. Some
subtle shifts have occurred and could have implications on SLR
while speed of the system promotes limited QPF; the result is a
very marginal decrease in snow amounts. NBM probabilities for
greater than 7 inches remain fairly low and relegated to
southern Vermont while other statistical analysis puts of to a
30% chance for exceeding 7 inches. As such, have opted to keep
the watch out. Moisture transport (IVT) projections of the 250
kg/ms do show significant moisture transport into north-central
Vermont suggesting a period of up to 0.25" of liquid equivalent
pushing into the Chittenden County to NEK areas. I`d like to see
slightly higher IVT to support snowfall greater than 4 inches,
but this could produce totals generally 2-4 inches with a few
spots seeing 5 inches in portions of northern Vermont. All
locations from Washington County to the Watch area are on the
edge of needing an Winter Weather Advisory while southern
Vermont will likely exceed 4 inches, but the question is will
they exceed 7 inches moving southern locations into Winter Storm
Warning territory. Speed of this system will be the main
limiting factor with the system exiting Tuesday night. Looking
at box and whisker plots for the current forecast is at the
75th percentile mark with based on WPC probabilities, suggesting
potential for knocking totals down another inch or so if
current model trends hold.
Wednesday will be the lull between systems. Some lake enhanced
showers may begin Wednesday afternoon as flow turns more
southwesterly ahead of an arctic front approaching the
Northeast. Temperatures are expected to be around average
Wednesday with highs in the upper 20s to low/mid 30s.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 119 PM EST Monday...Long term impacts include snow showers and
snow squalls on Thursday, followed by bitterly cold
temperatures/wind chills on Thurs night into Friday.
Conditions still look favorable for snow showers and embedded
heavier snow squalls on Thurs associated with arctic boundary. The
locally developed snow squall parameter is still highlighting values
of 2 to 4 acrs the SLV at 12z Thurs and into central/southern VT
around 18z Thurs, and exiting our cwa by 21z Thurs. Latest guidance
shows sharp convergence with arctic boundary with favorable axis of
strong 925mb fgen forcing, and moderate 3 hr pres rise couplet on
backside, supporting snow squall with gusty winds. The only limited
factor may be fropa timing and the associated llvl instability/lapse
rates from minimal sfc heating. NAM/GFS both indicate sharply
falling 925mb temps from -4C to -5C at 12z to -15C to -17C by 21z
Thurs, supporting the potential for a flash freeze. Always difficult
to determine if snow melts or if wind blows snow off the roads, but
potential for a flash freeze is something we will continue to watch
closely. Given the sharpness of the boundary/convergence and
dynamics aloft, would expect any snow squalls to quickly drop sfc
vis <1/4SM, localized wind gusts to 35 mph, and a burst of 1 to 2
inches of snow in 20 mins or less, creating very hazardous travel
conditions on Thurs. Timing looks to be around the morning commute
acrs northern NY and mid morning to mid aftn for most of VT,
including the CPV.
Moderate to strong llvl caa continues on Thursday night with progged
850mb temps falling btwn -18C and -22C by 06z Friday. Difficult to
determine how cold temps get, given gradient, but have values
ranging from -5F SLK to 10F near BTV, due to the warmer lake waters.
Given the extreme instability a few cold air funnels will be
possible over Lake Champlain on Thursday night/Friday morning, along
with some lake effect snow flurries. Limiting factor for additional
snow showers wl be depth of moisture. Wind chills wl be near 0F
valleys to -20F acrs the higher summits late Thurs into Friday.
Mid/upper lvl trof prevails into next weekend with below normal
temps and periods of snow showers possible. Best potential for
accumulating snowfall would be associated with another arctic
boundary and s/w energy late Sat into Sunday. Highest pops and
greatest potential for a light snowfall wl be acrs northern NY and
the mtns of northern/central VT. Temps only in the upper teens to
mid 20s Friday, warm into the mid 20s to lower 30s on Sat, before
cooling back into the upper teens to mid 20s on Sunday/Monday. Lows
generally in the single digits and teens, except lower 20s in the
CPV ahead of boundary on Sat night.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Through 18Z Tuesday...Any lingering MVFR cigs at our mtn taf
sites will become VFR in the next 1 to 3 hours. Gusty northwest
winds 10 to 15 knots with gusts 20 to 25 knots will become 5 to
10 knots by sunset. Next aviation challenge will be arrival time
of snow on Tuesday morning from southwest to northeast across or
taf sites and associated IFR visibilities. Expecting light snow
with visibilities between 1-2SM (IFR) to develop between 11-13z
on Tuesday with intervals of moderate snow likely with LIFR
(1/2SM) conditions mainly south of a SLK to BTV to 1V4 line by
15z Tuesday. CIGS generally drop into the MVFR range as the snow
arrives on Tues morning with some periods of IFR CIGS possible
in the heavier snow bands. Winds will shift to the
south/southeast at 4 to 8 knots, except northeast at MSS on
Tuesday.
Outlook...
Tuesday Night: MVFR/IFR conditions possible. Chance SN.
Wednesday: VFR. NO SIG WX.
Wednesday Night: Mainly VFR, with local MVFR possible. Chance SN.
Thursday: Mainly VFR, with local MVFR possible. Windy with gusts
to 30 kt. Chance SHSN.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.
Friday Night: Mainly VFR, with local MVFR possible. Slight chance
SHSN.
Saturday: Mainly VFR, with areas MVFR possible. Chance SHSN.
&&
.MARINE...
A Lake Wind Advisory remains in effect with westerly flow
producing frequent gusts in excess of 25kts. These speeds may
slow a bit by daybreak, but will increase with gusts frequently
exceeding 25kts again behind the front as background flow turns
more northwesterly driving a northerly wind across Lake
Champlain. Waves of 2 to 4 feet are expected into this afternoon
before winds subside.
&&
.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 Tuesday to 1 AM EST
Wednesday for VTZ003>009-017.
Winter Storm Warning from 7 AM Tuesday to 1 AM EST Wednesday
for VTZ010-011-018>021.
NY...Winter Weather Advisory from 7 AM Tuesday to 1 AM EST
Wednesday for NYZ034-035.
&&
$$
SYNOPSIS...Boyd
NEAR TERM...Boyd
SHORT TERM...Boyd
LONG TERM...Taber
AVIATION...Taber
MARINE...Team BTV
EQUIPMENT...Team BTV
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