133
FXUS61 KBTV 201721
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
1221 PM EST Sat Dec 20 2025
.SYNOPSIS...
In the wake of our Friday system, much quieter weather is
expected on Saturday, before more winds develop on Saturday
night into Sunday. Gusty channeled flow from south winds,
locally up to 40 mph will be possible tonight as a clipper
system rides north of the border. Mountain snow chances will
continue through the weekend as a parade of quick moving system
traverse the region through early next week. Seasonable to just
above average temperatures and continued snow chances are likely
heading into the holiday travel period.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 647 AM EST Saturday...As an arctic boundary continues to
move southeastward this morning, shallow moisture will be
dragged along with it as brief ridging builds in for today. Most
areas should see some sun this morning before clouds return
this afternoon. Winds will also weaken to near calm by midday
with a wind shift to the south taking place over the course of
the day. Temperatures remain on the cool side in the 20s for
most of the day before southerly winds and waa kicks in with
temperatures reaching their highs Saturday evening, and will
continue to increase into Saturday night.
A clipper system will ride north of the border, with a trend
that has taken the system further north, resulting in stronger
waa. Temperatures by Saturday evening should reach back to
freezing and perhaps into the mid 30s for the Champlain and St.
Lawrence Valleys overnight. These warmer temperatures will be
ushered in by a strong 60-70 kt jet at 5000ft agl. Given the
northerly trend of the center of the low well north of the
international border, precipitation chances have lowered with
mainly just chances near the international border and in the
Adirondacks. While precipitation should start as snow for most
areas Saturday evening, rain will mix in across the St. Lawrence
Valley overnight. With the center of the low to the north,
chances of impacts from the associated cold front will increase.
The NAM soundings suggest the presence of about 100-150 J/kg of
CAPE associated with the boundary over northern New York with
decent convergence along a thin area of frontogenesis. By Sunday
morning there is a increased chance of some heavier bands of
showers, with embedded snow squalls possible which could impact
travel Sunday morning, particularly in the St. Lawrence Valley.
Concurrently ahead of this boundary will be a weak lake effect
band off Lake Ontario. While the flow regime will be favorable
for banding across southern St. Lawrence County, temperature
profiles will limit snow, and will likely be more rain under the
band into Sunday morning with temperatures in the low to mid
30s.
With precipitation chances lowered, more mixing will take place
with channeled flow in the wider valleys as the surface warms,
but 850mb temperatures undergo caa leading up to sunrise Sunday
morning. HREF probabilities suggest an 80% chance of seeing >40
mph gusts at BTV Saturday night. Also concerning is that there
is good agreement in 40kt winds at 1000ft on GFS/NAM/HRRR
soundings, which would not take much forcing to mix these winds
to the surface. Consequently, have increased gusts, especially
in the CPV Saturday night up to 30 to 35 mph, with future
updates likely to increase further if trends continue.
Temperatures will continue to be on the rise Saturday night into
Sunday morning following a non-diurnal curve with little
typical overnight cooling taking place. Temperatures by Sunday
morning will be about 10 degrees warmer than the same time this
morning.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
As of 139 AM EST Saturday...A cold front will slowly pass
through the region Sunday morning from west to east. The band
will lose most of the forcing associated with it as the parent
system lifts north further away from the area, drawing most of
the energy and moisture with it. Main concerns will be continued
gusty winds during the day Sunday across the northern
Adirondacks and Champlain Valley with gusts 25 to 35 mph. Lake
effect showers will wain with the passage of the boundary
shifting winds and the axis of the band south of the region.
Temperatures will fall back to single digits and low teens
Sunday night with good caa. Wind chills will be near 0 to the
negative single digits with gusts continuing. While moisture
will be limited, northwest flow with orographic lift should keep
some slight to chance PoPs across the western facing slopes of
the northern Adirondacks and northern Greens Sunday night into
the day Monday. Snow ratios will be 15-20:1 with any snow that
falls on the more light and fluffy consistency. A few inches of
snow is possible close to Jay Peak and in the Adirondacks.
Temperatures will be relatively seasonable in the low to mid 20s
with weaker winds Monday.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
As of 139 AM EST Saturday...A clipper system approaching from
the central Great Lakes region will bring the potential for
light snowfall across northern NY and VT, likely starting during
the pre- dawn hours Tuesday across northern NY, with stratiform
snow overspreading the remainder of Vermont through mid-
morning. There is a low chance of a rain/snow mix during Tuesday
afternoon as boundary layer temperatures warm into the 33-36F
range in the immediate Champlain Valley and the St. Lawrence
Valley. That said, snow should be the predominant precipitation
type, with some minor travel impacts due to snow covered
roadways expected throughout Tuesday. Based on present
indications, a 2-4" snowfall is generally expected, with the
bulk of that falling during the daylight hours on Tuesday.
Once the clipper system translates to our east, sfc high pressure
will briefly crest over the North Country for Christmas Eve Day.
Generally dry conditions expected with seasonable high temperatures
in the mid-upper 20s, except lower 30s for the valleys of s-central
Vermont. Once the sfc ridge axis shifts to our east, breezy S-SW low-
level flow will redevelop across our region for Christmas Day. This
will allow temperatures to warm into the 35-40F range for Christmas
afternoon. Modest low-level warm advection may be sufficient to
result in some light rain/snow showers on Christmas, but overall
forcing appears weak at the present time. Indicated 30-50% PoPs for
rain or snow showers, and slightly higher (60%) across the higher
summits. Above normal temperatures will continue into Friday with
highs near 40F in most locations.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Through 18Z Sunday...Mainly VFR through the forecast period with
low level wind shear being the greatest impact. BKN/OVC VFR
cigs expected generally in the 080-120 AGL range through 02Z,
then 035-070 AGL mainly thereafter, trending SCT after 13Z
Sunday. Winds trending south to southwesterly over time and
gusty into the 20-30kt range from 00-12Z, during which enhanced
southwesterly LLWS in the 40-50 kt range expected at selected
terminals. Frontal system then crosses area in the 10-15Z time
frame after which winds trend westerly, though remain gusty to
30 kts. Precipitation chances fairly low through the period, but
VCSH and/or PROB30s for a few snow showers will be offered at
selected terminals generally in the 01-13Z time frame in advance
of the front.
Outlook...
Sunday Night: VFR. NO SIG WX.
Monday: VFR. Chance SHSN.
Monday Night: Mainly VFR, with local MVFR possible. Chance SN.
Tuesday: Mainly MVFR and IFR, with local VFR possible. Definite
SN.
Tuesday Night: MVFR. Chance SHSN.
Wednesday: Mainly VFR, with local MVFR possible. NO SIG WX.
Wednesday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Christmas Day: Mainly VFR, with areas MVFR possible. Slight
chance SHSN.
&&
.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...None.
NY...None.
&&
$$
SYNOPSIS...Danzig
NEAR TERM...Danzig
SHORT TERM...Danzig
LONG TERM...Banacos
AVIATION...JMG
EQUIPMENT...Team BTV
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