630
FXUS61 KBTV 212340
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
740 PM EDT Sat Mar 21 2026
.WHAT HAS CHANGED...
As of 255 PM EDT Saturday...
No major changes were made to the overall forecast. A light
glaze of ice was added to portions of the Adirondacks and
eastern Vermont for tomorrow afternoon.
&&
.KEY MESSAGES...
As of 255 PM EDT Saturday...
1. A clipper will move across the North Country and northern
New York tonight into Monday morning bringing widespread snowfall
and a change to a rain/snow mix across southern Vermont and the St.
Lawrence and Champlain Valleys tomorrow afternoon.
2. Seasonally cool and drier to start next week.
3. Several weather disturbances are projected to traverse
Vermont and northern New York for the rest of the week.
&&
.DISCUSSION...
As of 255 PM EDT Saturday...
KEY MESSAGE 1: A Winter Weather Advisory remains in effect from
8 PM this evening through 8 AM Monday morning for the Adirondack
region in New York and the spine of the Green Mountains eastward
in Vermont for 3 to 6 inches of snow and a light glaze of ice. Zonal
flow will begin to break down this evening as a weak surface
low moves across the Great Lakes Region this afternoon. The
surface low is currently meandering across the upper Midwest
with mid to high level clouds advecting into the region from the
northwest. Precipitation will begin as widespread snow from west
to east beginning in northern New York by 8 PM and arriving in
Vermont by Midnight tonight. Models have mainly stabilized on
the low center track across southern Vermont and along the
southern Adirondacks. This favors more snow across the North
Country and areas north of US-4 initially. HREF mean snow rates
show 0.5-0.75 inch/hr rates which is supported by a shallow DGZ
thicknesses between 3-5kft at 12,000ft on HRRR model soundings.
As the system progress eastward tonight, 850mb frontogenesis
will increase between 1 AM and 10 AM when the highest snowfall
amounts are expected. Snowfall amounts will vary from 1-3"
across the St. Lawrence and Champlain Valley, with possibly 6 to
10 inches across the upslope favored summits in the western
slopes of the Green Mountains. The snow will be of a wet
character with snow ratios favoring ratios from 7-10:1, with
lower ratios across southern Vermont.
Beyond 10 AM, a dry slot may entrain some dry air into the
Champlain Valley and portions of southern Vermont which will
lead to a drying of the mid to upper levels, and thus a loss of
cloud ice in the DGZ. This dry slot will also be accompanied by
temperatures in the 32-36 degree range which will could lead to
some mixed precipitation in the form of snow and rain in a
narrow band from Newcomb, NY to Middlebury and White River
Junction in Vermont. Furthermore, as we lose cloud ice tomorrow
afternoon, and moisture lingers at the surface, precipitation
may trend towards drizzle and freezing drizzle in the Champlain
Valley and southern Vermont. Within this mixed precipitation and
potential freezing drizzle, up to a light glaze of ice is
possible. Portions of southern Rutland and Windsor counties may
remain completely rain through the event. Any freezing
precipitation will be short lived, as the DGZ will sink closer
to the surface back into the shallow moisture by tomorrow
evening. As with last night, some patchy freezing fog may
develop in the low lying areas Sunday night, but confidence is
low so it was not included in the current forecast. Main impacts
from this event will include hazardous travel beginning tonight
through the Monday morning commute from slick roads.
KEY MESSAGE 2: Following the clipper system, a 1030mb area of high
pressure will build into the region for Monday night into Tuesday.
Low to mid level moisture will dry out as subsidence from the high
and drier southerly air will entrain into the area. Skies should
become mainly sunny to mostly sunny, especially over the St.
Lawrence on Tuesday. Clouds may linger across eastern Vermont with a
weak trough hanging on in the wake of our clipper system Sunday.
Temperatures under the high will generally be seasonable to 5
degrees below normal, particularly in northern New York and
eastern Vermont, as we will still be under the influence of a
dominating upper level trough, which is fairly normal for late
March.
KEY MESSAGE 3: Tuesday night into Wednesday will begin with a
reinforcing cold front impacting the region. Surface low pressure
will be well north with a tenuous strand of moisture. Scattered snow
showers will occur overnight into early Wednesday morning, mainly
for favored western slopes where orographic lift can help the lack
of forcing and moisture. Wednesday itself should be cool and
somewhat breezy as a 1032mb surface high builds across Quebec
Province.
Active channeled flow across the region will bring the next system
in Wednesday night into Thursday morning. Forecast scenarios are
split on the low position and the orientation of track. One cluster
has low pressure ejecting northeast with a surge of warm air on
Thursday. Other clusters depict the low tracking west to east with a
mix of rain and snow depending on elevation with cooler conditions
overall. With ensembles in a roughly 50-50 split, it seems unwise to
commit to any particular solution. The pattern split continues down-
forecast. Cooler than normal temperatures are present across either
end of diverging model guidance, but the end of next week could
either be dry, or it could have another round of light snow showers.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...Current radar shows light snow quickly
angling toward the St Lawrence River Valley this evening, but
surface dwpts in the 20s has resulted in precip not reaching the
ground. Expect IFR vis in light snow to develop at SLK/MSS
between 2-4Z and 4-6Z for PBG/RUT/BTV and after 06z for MPV/EFK.
Cigs lower from VFR to MVFR conditions as snow develops with IFR
visibilities prevailing at most sites thru 12z. As warmer
surface temps develop, expect some mix with rain with MVFR vis
developing in our valley taf sites by 14z Sunday. Precip should
exit our taf sites by 18z, with lingering areas of
drizzle/freezing drizzle developing, along with lowering ceiling
back toward IFR, especially Champlain Valley with developing
northwest winds after 21z. This wind direction combined with
strongly blocked flow, will result in a long duration of IFR
cigs at RUT/BTV thru Sunday night, with additional IFR cigs
likely at SLK/MPV and EFK. Some localized low level wind shear
is likely after midnight tonight.
Outlook...
Sunday Night: MVFR/IFR conditions possible. Chance SN, Slight
chance FZDZ.
Monday: Mainly MVFR, with areas VFR possible. Chance SN.
Monday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. Chance SN.
Wednesday: Mainly VFR, with areas MVFR possible. Chance SHSN,
Chance SHRA.
Wednesday Night: Mainly VFR, with local MVFR possible. Chance
SHSN.
Thursday: Mainly MVFR, with areas VFR possible. Chance SHRA,
Chance SHSN.
&&
.EQUIPMENT...
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. Please contact us if you
observe winds significantly deviating from the recreational
forecast.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Winter Weather Advisory until 8 AM EDT Monday for VTZ003-004-
006>008-010-017>021.
NY...Winter Weather Advisory until 8 AM EDT Monday for NYZ027-030-
031-034.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Haynes/Danzig
AVIATION...Taber
EQUIPMENT...NWS BTV
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