963
FXUS61 KBTV 222346
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
646 PM EST Sat Feb 22 2025

.SYNOPSIS...
A weak disturbance and associated moisture will produce a round of
mostly mountain snow showers tonight into Sunday morning. Snowfall
will range from a dusting in the valleys to 2 to 4 inches across the
northern Adirondacks and northern Green Mountains of Vermont.
Temperatures will only cool a few degrees overnight and warm into
the upper 20s to mid 30s on Sunday. Another cool night is expected
on Sunday night, but temperatures warm well into the 30s to near 40
for Monday and Tuesday.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 633 PM EST Saturday...Light virga snow showers are moving
into northern New York out of Canada. It will take a couple
hours of moistening to get much in the way of snowfall to reach
the ground. Overall, there may be about an hour delay from the
previous forecast to get accumulating snow, but nothing to
really change the overall message that a light snowfall will
occur overnight into Sunday morning. Other weather parameters
are right on track with only minor adjustments needed for
temperatures based off of latest observation trends.

Previous Discussion....GOES-16 mid lvl water vapor imagery
clearly shows our s/w trof and associated mid lvl moisture over
the central Great Lakes this aftn, with some cooling cloud tops
on the latest IR product. This s/w trof and associated pocket of
enhanced 850 to 500mb moisture wl quickly overspread our region
from west to east this evening. Clouds wl thicken and lower
with light snow shower activity developing acrs the SLV by 03z
and into the northern VT mtns by 06z. Initially bl conditions
are dry with sfc dwpts only in the single digits, but eventually
enough saturation occurs for flakes to make it to the sfc.
Given southwest 925mb to 850mb flow of 25 to 40 knots tonight,
qpf/snowfall wl be impacted by the trrn, with our typical
shadowing here in the CPV and very little precip over
southern/eastern VT areas anticipated. I have the highest
pops/qpf and snowfall over the northern Dacks into the northern-
central mtns of VT tonight, where 2 to 4 inches of snowfall is
possible by 15z Sunday, while only a dusting to an inch or so
elsewhere. Temps this evening only drop a few degrees with
increasing clouds and south/southwest winds prevailing, expect
lows upper teens to mid 20s, except l/m teens NEK of VT, where
clouds take the longest to develop and dwpts are the lowest.

Lingering snow showers wl prevail in the mtns associated with
westerly flow in the 925mb to 850mb layer, along with some slowly
departing mid lvl moisture. Did note latest NAM/GFS shows a weak 5h
vort approaching our northern VT cwa around 18z Sunday, which
combined with steepening llvl lapse rates and weak elevated
instability per sounding data, should help to enhance some
additional convectively like snow showers over the mtns on Sunday
aftn. Highest chc pops wl be over the northern/central Greens into
parts of the NEK. Progged 925mb temps warm btwn -5C and -7C wl
support highs upper 20s to mid 30s on Sunday. Sunday night is quiet
but low temp fcst wl be tricky, especially deeper valleys of
central/eastern VT, where large spread occurs in guidance. For
example MAVMVL is 5, while METMVL is 18, the NBM is 12, thinking
some clearing develops associated with weak sfc ridging and combined
with deep snow pack, have trended toward the cooler MAV. This
general idea does support a shallow/sharp inversion with warmer
midslopes/ridges, which I have tried to show with lows ranging from
single digits to mid/upper teens acrs our region. If more clouds
lingering and winds don`t decouple, lows wl be much warmer than crnt
fcst.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 333 PM EST Saturday...Surface low pressure will cross the James
and Hudson bays in Canada early next week, advecting moist, milder
air and a low level jet into northern New York and Vermont Monday.
Cloud cover will be on the increase throughout the day ahead of a
prefrontal trough with showery precipitation potentially arriving in
the St. Lawrence Valley and far northern Vermont in the afternoon,
increasing in coverage for northern New York and northern Vermont
throughout the evening. Overnight, highest chances of precipitation
will shift to northern Vermont and the Northeast Kingdom. The 850mb
flow will peak at about 50-60 knots out of the southwest, resulting
in some precipitation shadowing for the Champlain Valley and breezy
conditions at the surface, perhaps 25-30 knot gusts out of the south
Monday afternoon.

Low level forcing and convergence continue to look lackluster, and
models are trending the system farther north from run to run, so
precipitation is not expected to be impressive, perhaps up to 0.10"
at high terrain for Adirondacks and northern Greens Monday through
Monday night, but more widespread 0.00-0.05" elsewhere. Temperatures
will be supported by the influx of milder air from the south, rising
to the upper 30s to lower 40s Monday afternoon. Monday night lows
will also fail to fall significantly, resulting in temperatures only
as low as the lower to mid 30s.

Because of this, we will see many valley and lower elevation
locations report rain or a rain snow mix at times, while colder,
higher elevations could have snow for much of the time. Snow amounts
only up to about an inch even at the peaks are anticipated, due to
the combination of low precipitation amounts and low snow ratios
since the air mass will be moist and mild. Snow will be slushy in
character, but there will not be enough of it to warrant utility
concerns. We`ll be watching the warm temperatures and rain for
melting of snowpack, but rainfall amounts look minimal and colder
nights following should allow the snowpack to freeze up again.
Overall, a low impact, minor nuisance system forecast for the start
of the work week.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 333 PM EST Saturday...An active pattern continues for the rest
of the week, though no overly impactful systems appear on the
horizon. Weak low pressure will struggle to develop across the
forecast area Tuesday and Tuesday night, bringing additional snow
and rain showers, mostly to northern and northwestern areas.
Temperatures will continue to be quite mild Tuesday, reaching up to
the upper 30s and lower 40s during the afternoon, then falling to
the mid 20s to lower 30s overnight. This will allow for another rain
and snow mix, turning to snow Tuesday night.

Wave after wave of shortwave will flow through the forecast area
following this, causing a wide range of possible temperatures. Our
forecast is highs in the upper 20s to lower 40s and lows in the
single digits to lower 20s, but there is still a lot of variability
amongst model solutions. What can be noted from guidance is that
temperatures will gradually trend downward and colder toward the end
of the week and into next weekend. We continue to monitor the next
potentially significant system next weekend, where surface low
pressure appears to cross over or a bit north of the forecast area
followed by a modestly deep trough.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...VFR conditions continue with virga snow
showers falling in northern New York. Moistening will take a
couple/three hours before measurable amounts begin to occur,
maybe by 03Z. CIG/VIS reductions will shortly follow west to
east, but overall pushed back by about an hour based on current
timing associated with MMRS radar, satellite imagery, and
surface observations. MVFR chances increase after 03Z for
MSS/SLK with better chances for IFR after 05Z. IFR chances will
depend largely on shower intensity for other terminals, but
could see brief periods of 2SM in the 06-12Z time frame. MPV
will be interesting today with potential for pervasive MVFR
CIGs should mountain waves set up over the terminal. Otherwise,
VFR returns to most locations after 12-15Z with westerly breezes
gusting to around 15kts. MSS will be the breeziest spot with
gradient aligning with terrain favoring gusts 18-23kts before
trough passage from 03-12Z then shift westerly. Turbulence will
be widespread around ridge level altitudes due to a moderate
southwest-northeast 40kt lljet moving west to east from 00-12Z.

Outlook...

Sunday Night: Mainly VFR, with local MVFR possible. Slight chance
SHSN.
Monday: VFR. Chance SHRA, Chance SHSN.
Monday Night: Mainly VFR, with local IFR possible. Chance SHRA,
Chance SHSN.
Tuesday: Mainly MVFR, with local IFR possible. Chance SHRA,
Chance SHSN.
Tuesday Night: Mainly IFR, with areas MVFR possible. Chance SHSN,
Chance SHRA.
Wednesday: Mainly MVFR, with areas IFR possible. NO SIG WX.
Wednesday Night: Mainly MVFR, with local IFR possible. Chance
SHSN.
Thursday: Mainly IFR, with local MVFR possible. Chance SHSN,
Chance SHRA.

&&

.EQUIPMENT...
The Mount Ascutney NOAA Weather Radio transmitter, serving
portions of eastern Vermont, is currently out of service. The
earliest date of restoration is now Tuesday, February 25th
following a delay. We apologize for any inconvenience.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Taber
NEAR TERM...Boyd/Taber
SHORT TERM...Storm
LONG TERM...Storm
AVIATION...Boyd/Taber
EQUIPMENT...WFO BTV