314
FXUS61 KBTV 210547
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
1247 AM EST Thu Nov 21 2024
.SYNOPSIS...
Several rounds of precipitation are expected for the rest of the
week and into the weekend. We will see much needed rain and summit
level snow initially. Some gusty easterly downslope winds could take
place Thursday night. After a brief break on Friday, precipitation
will resume overnight and then through Sunday as weather transitions
towards orographic, northwesterly flow type precipitation with snow
levels falling towards 2000 foot elevation. Although the larger
upper low will depart early next week, we will transition into
a showery weather pattern with little variation in temperatures.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 923 PM EST Wednesday...A few minor adjustments were made
to temperatures and sky cover with this update, with the
current forecast in good shape. Some mist and low clouds
continue to linger across portions of the Champlain Valley,
although increasing southerly winds will limit this development.
Temperatures across the region are quite variable given the mix
of clear skies and increasing cloud cover from the approaching
front. Temperatures across Vermont are around freezing, while
northern New York is several degrees warmer and the St. Lawrence
Valley is in the low 40s.
Previous Discussion...Upper level low pressure will dive into
the Great Lakes region tonight, lifting an occluded frontal boundary
towards the forecast area from the southwest, causing an increase in
clouds across northern New York and Vermont throughout the night. A
secondary low pressure center will develop along the Mid-Atlantic
Coast tonight, progressing towards Long Island, New York, tomorrow
(Thursday), and upper level low pressure will transfer towards the
coast as well. Lows tonight will be relatively mild in the 30s for
most, several degrees above seasonal averages.
Rain is most likely to arrive in St. Lawrence County before dawn
tomorrow morning, then continue to spread across the forecast area
from southwest to northeast throughout the day. Snow levels could
fall as low as 1500-2500 feet elevation tomorrow for northern New
York and the southern Greens, keeping any potential snow at that
height or higher. There is the potential for some very light
freezing rain to occur at higher elevations as the occluded front
undercuts milder air aloft, creating an inversion on the mountains.
This would be limited to the first few hours of the day tomorrow and
mostly above 2500 feet elevation. Highs tomorrow will be slightly
above seasonable in the 40s under thick cloud cover and steady
precipitation.
The idea of mostly rain with some snow at high elevations will
continue tomorrow night as vertically stacked low pressure meanders
northward in the Hudson Valley/Catskills area, stalling and
weakening. This will allow for precipitation to become more showery
in nature over the forecast area, and towards dawn Friday, snow
levels will continue to drop. However, models are indicating a
possible push of frontogenetical forcing as an occluded front lifts
north through our forecast area, which may indicate another round of
steadier precipitation. Gusty winds 10-30 knots are anticipated
Thursday night out of the east and northeast due to the position of
the low pressure to our south. Highest wind gusts are expected to be
seen due to downsloping on western mountain slopes. Lows will be on
the rebound tomorrow night in the upper 30s to lower 40s, once again
relatively mild compared to climatological normals.
Overall precipitation amounts through Thursday night are expected to
reach 0.30-1.60" with anticipated snowfall amounts of up to 11
inches in the higher peaks of the Adirondacks and up to 6 inches in
the higher peaks of the southern/central Greens. No snow is forecast
to accumulate lower than 1500 feet of elevation, though it`s not out
of the question that snowflakes could mix in at 1000 feet and
higher, especially in heavier precipitation.
&&
.SHORT TERM /FRIDAY NIGHT/...
As of 324 PM EST Wednesday...Friday continues to trend drier due to a
modeled dry slot wrapping into the system over the forecast area.
Low pressure will slide south back towards the Lehigh Valley, and
high temperatures here in the BTV area will have the chance to rise
into the mid 40s to lower 50s with breaks in the clouds. Scattered
showers, particularly upslope on eastern slopes, are anticipated
throughout the day before low level flow turns northwesterly
overnight. Another low pressure could twirl back towards the
forecast area along the Maine Coast, though models begin diverging
in solutions at this point of the forecast. Snow levels appear to
fall Friday night as lows reach the upper 20s to mid 30s. Additional
precipitation Friday and Friday night will be up to 0.40" with
additional mountain snow of up to 4 inches possible as snow levels
fall as low as 1,500-2,000 feet elevation.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 324 PM EST Wednesday...Another round of elevationally dependent
rain/snow is expected on Saturday, especially for higher elevations
of Vermont. A coastal low will be located off the Maine Coast, which
will wrap Atlantic moisture up and around the low and into portions
of inland New England. Noting still some spread among models in the
exact track of the low, but the setup will allow for another wave of
snow/rain inland. Placing this last wave of wrap around
precipitation is difficult with the spread in low track, but current
guidance suggests a few inches of snow is not out of question for
the higher elevations (above 2000 ft) of the Green Mountains with
lower amounts westward into the Adirondacks. Precipitation that
falls below 2000 feet will fall mainly in the form of rain, although
a rain snow mix is possible down to 1500 ft elevation.
As the coastal low deepens, the pressure gradient will tighten over
New England and northwesterly wind gusts will increase to the 15 to
25 mph range Saturday through Sunday. Locally stronger gusts in the
25 to 35 mph range are expected over mountain summits and also over
the northern Champlain Valley, especially Saturday night into
Sunday.
Any lingering precipitation along with gusty winds will come to an
end Sunday night into Monday morning with high pressure building in.
The dry weather will be short-lived, however, as the pattern
remains active and another system brings chances for showers
Monday night into Tuesday.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Through 06Z Friday...Maritime air is resulting in pockets of
900-2800 ft agl ceilings, but is at least starting to clear fog
as an occluding front approaches. Ceilings are expected to trend
down across all terminals, but with some variability with
terrain as east to southeast flow increases in the mid-levels
and results in pockets of terrain shadowing for areas like
KRUT/KEFK/KSLK. Precipitation will be very slow to lift
northeast, but some rain could approach KRUT and KMSS about
12z-14z. The front will decay, though, with precipitation
slowing and breaking up before redeveloping after 18z. With
increasing rates, this could reduce visibilities to 3-5SM. Noted
a PROB30 of RASN at KSLK from 22z to 01z Friday. It appears
after 03z, that precipitation could begin to break up again as
winds at 2000 ft agl increase up to 40 to 45 knots, mainly over
southern Vermont. Have noted the LLWS for now at KRUT, but there
could be a trend towards more showery conditions and
intermittent increases in ceilings. Additional showers and winds
expected beyond 06z Friday.
Outlook...
Friday: Mainly VFR, with local MVFR possible. Likely SHRA.
Friday Night: MVFR/IFR conditions possible. Likely SHRA, Chance
SHSN.
Saturday: Mainly MVFR, with areas IFR possible. Likely SHRA.
Saturday Night: Mainly MVFR, with local IFR possible. Chance
SHRA.
Sunday: Mainly MVFR, with areas VFR possible. Chance SHRA, Chance
SHSN.
Sunday Night: Mainly VFR, with areas MVFR possible. Slight chance
SHSN.
Monday: Mainly VFR, with local MVFR possible. Slight chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Storm
NEAR TERM...Kutikoff/Storm
SHORT TERM...Storm
LONG TERM...Duell
AVIATION...Haynes
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