235
FXUS61 KBTV 191907
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
207 PM EST Mon Jan 19 2026
.WHAT HAS CHANGED...
As of 207 PM EST Monday...Winter Weather Advisory in northern
New York now ends at 5 AM. Most of the snow will end soon after
midnight.
&&
.KEY MESSAGES...
As of 207 PM EST Monday...
1. Lake effect snow will impact southern St Lawrence county
today through Tuesday. Snow squalls will also be possible
Monday evening, especially across northern New York. Outside of
snow squalls, winds will remain gusty with periods of low
visibility expected.
2. An arctic airmass is expected to bring dangerously cold
temperatures to the region this weekend.
3. Snow showers and possible snow squalls may lead to hazardous
travel conditions at times, especially on Thursday.
&&
.KEY MESSAGES...
As of 150 PM EST Monday...
- Periods of snow showers with brief embedded heavier snow
squalls possible later today and again on Thursday, creating
localized hazardous travel.
- 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 150 PM EST Monday...
.KEY MESSAGE 1: A couple of deepening low pressure systems
passing well to our northwest, and their associated cold fronts,
will bring us scattered snow showers with embedded snow squalls
possible later today and tonight, and again on Thursday. Some
areas of light snow also are expected for tomorrow and Wednesday
but less significant.
For today, difficult travel will be primarily in western
portions of northern New York due to a combination of lake-
effect and non lake- effect snow showers organized by a pre-
frontal trough. Hi-res model guidance continues to show bands
of intense snow waffling across St. Lawrence and Franklin
counties, with heaviest snowfall amounts still in southern St.
Lawrence County. However, compared to previous forecasts, the
duration of snowfall has trended shorter, leading to slightly
lower snowfall amounts in the Advisory area, now mainly 2 to 5
inches.
That being said, impacts are unchanged related to rapid changes in
conditions when driving with sharp reductions in visibility and snow
covered roads. This system`s low track will support efficient mixing
of southwesterly winds such that gusts of 30 to 40 MPH in much of
northern New York will resulting in blowing of falling snow, with
greatest risk between 5 and 9 PM. An additional surge of gusty winds
may also occur closer to midnight, although snowfall chances will be
diminishing at that time. East of the Adirondacks, and including all
of Vermont, scattered snow showers are also expected but with more
localized impacts with very brief heavy snowfall rates in a couple
of showers. We have pretty large dew point depressions out there
with low level dry air likely inhibiting valley snowfall potential
and moisture transport; higher elevation passes are more likely to
see significant precipitation tonight. It appears greatest chances
for this activity is between about 7 and 10 PM.
The bulk of this event will be over with in the early morning hours,
hence the earlier end time for the Winter Weather Advisory, as a
single, intense snow band develops off of Lake Ontario soon after
midnight and the westerly flow shifts precipitation south of our
forecast area in New York. Additional chances for lake-effect, or at
least lake-enhanced, snow showers during the day Tuesday will be
focused more in Adirondacks and in central Vermont and with
more limited impact. Strong cloud layer west-southwest flow and
ample instability with steep low level lapse rates as an upper
level trough passes through should be enough for at least some
snowfall. This snow shower activity, as well as yet snow showers
later Wednesday into Wednesday night, does not look capable of
producing widespread travel concerns, but note gusty winds and
localized low visibilities will be possible during these
periods.
Another round of snow showers with brief embedded heavier snow
squalls are possible on Thursday as 1004mb clipper like system
passes to our northwest. The locally developed snow squall parameter
indicates values in the 2 to 5 range on Thursday aftn, especially
acrs northern NY into the mtns of northern VT. Sfc based CAPE values
off the NAM12 show readings in the 50 to 100 J/kg range with some
localized higher values, while moderate 925mb fgen forcing is
present with arctic boundary. However, similar to previous events
this winter, setup is not ideal for organized snow squalls, as sfc
convergence is limited as boundaries come in a series of waves.
Also, 700-500mb vorticity is shearing apart in the fast
west/southwest flow aloft, instead of digging with a deepening
mid/upper lvl trof acrs our fa. These factors suggest scattered to
numerous snow showers are likely with a few heavier embedded snow
squalls possible, especially northern NY, where some lake enhanced
moisture/instability is possible. Temps with southwest flow should
warm into the mid 20s to lower 30s. Given strong 925mb to 850mb
southwest flow ahead of approaching boundaries, anticipate the
typical downslope precip shadow here in the CPV and lower CT River
Valley.
.KEY MESSAGE 2: Forecaster confidence continues to increase for
a significant and dangerous arctic outbreak late week into this
upcoming weekend. Little change has been noted with regards to
thermal profiles with this 12z guidance package. Friday night
into Saturday will be an advection type cold with dangerously
cold wind chill values in the 20 to 40 degrees below zero with
radiational cold on Sat night into Sunday. Extreme cold warnings
and cold weather advisories will likely be needed for the
forecast area.
The core of the coldest 925mb to 850mb temps with sub 490 thickness
values are directly overhead btwn 03z and 12z Saturday. Progged
850mb temps range btwn -28C and -34C, while 925mb temps are in
the -24C to -32C, which supports lows -5F to -20F with wind
chills on Sat morning between -20F and -40F, coldest in the
mountains. Highs on Saturday will struggle to reach 0F in the
CPV with -5F to -10F in the mountain valleys. For Sat night a
1036 to 1040mb high pres builds into our cwa with very cold
925mb temps prevailing. This should allow for clear skies and
light winds with lows ranging from -25F to -30F SLK/NEK to -10F
to -20F elsewhere. Its interesting to view the NBM percentiles
for this outbreak, which shows the deterministic value of -3F
for MSS, -4F for SLK and +3F for BTV, while 50th percentile is -7F
for MSS/SLK and -2F for BTV, while 90th percentile is 0F, 2F,
and 8F respectively for highs Sat. For lows on Sat night the NBM
deterministic is -18F, -21F and -8F, while 50th percentile is
-27F, -30F and -12F for MSS/SLK and BTV respectively. I did
trend toward the 50th percentile for both highs and lows during
this time period. Temps slowly warm a few degrees on Sunday into
Monday, but still well below normal for mid/late January. No
significant snow is anticipated for late week into the upcoming
weekend.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Through 18Z Tuesday...Aviation challenge is timing of intervals
of IFR/LIFR snow showers and embedded snow squalls through this
evening. Currently a mix of IFR at SLK to VFR elsewhere with
radar imagery showing scattered snow shower activity increasing
in areal coverage. The highest probability of frequent IFR
conditions or lower will be at SLK/MSS through 00z this evening
with 30% to 50% probability at EFK/MPV and 20-30% at PBG/BTV
and RUT. Have utilized a combination of PROB30 and TEMPO groups
to highlight periods/intervals of IFR conditions thru this
evening. Also, brisk south to southwest winds 15 to 25 knots
will create some areas of blowing/drifting snow, along with some
reduced sfc vis. Conditions improve to VFR with MVFR cigs in
the mountains by midnight with mostly VFR by sunrise on Tuesday.
Winds shift to the west/northwest by Tues morning.
Outlook...
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Chance SN.
Wednesday Night: Mainly VFR, with local MVFR possible. Chance SN.
Thursday: Mainly VFR, with local MVFR possible. Chance SHSN.
Thursday Night: VFR. Slight chance SHSN.
Friday: VFR. Slight chance SHSN.
Friday Night: Mainly VFR, with local MVFR possible. 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...Winter Weather Advisory until 5 AM EST Tuesday for NYZ029-087.
&&
$$
DISCUSSION...Kutikoff/Taber
AVIATION...Taber
EQUIPMENT...NWS BTV
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