000
FXUS61 KBTV 261130
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
630 AM EST Sun Nov 26 2023

.SYNOPSIS...
Today will feature dry weather, but precipitation returns tonight as
a trough of low pressure crosses the region. We`ll see widespread
rain and higher elevation snow through Monday morning, tapering to
showers during the afternoon. Scattered mountain snow showers will
continue through Tuesday, but the next chance for more widespread
precipitation doesn`t arrive until late in the week.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 621 AM EST Sunday...No significant changes were needed to
the forecast with this update. Seeing a large break in the cloud
cover as anticipated, though clouds continue to linger over much
of northern NY into central VT. This clearing has allowed
temperatures to drop a little more than expected, and have made
adjustments accordingly. Any sunshine this morning will give
way to increasing clouds by afternoon. The forecast has that
part covered, so have just made some slight tweaks to sky cover
this morning to match the latest satellite trends.

Previous discussion...Still a complicated forecast for tonight
into Monday, with some slight adjustments made with this package.
However, overall thinking has not changed, as we`re anticipating a
quick shot of higher elevation snow/valley rain, with a few inches
of accumulation possible over 1500 ft.

First, today`s the quiet before the storm. High pressure currently
centered off the New England coast will continue to slide eastward
through the day while the upper trough moves into the western Great
Lakes. Although we should see a few sunny breaks this morning,
overall trend will be for increasing cloud cover ahead of this
latter system. Flow will trend toward the south/southwest, helping
temperatures to warm into the mid and upper 30s by this afternoon.
The vast majority of the day will be dry as any precipitation will
hold off until well after dark, mainly after 8 pm.

For tonight and Monday, we`ll be sandwiched between two surface low
pressure systems, the first of which will push eastward between
Hudson Bay and the Great Lakes, remaining well to our north.
Meanwhile, a second low will develop off the Mid Atlantic coast and
lift northeastward, strengthening as it does so. This secondary
system has trended further westward with the 26/00z guidance suite;
the consensus now brings it onshore into CT/RI, moves it briefly
into the western Gulf of Maine, and then back onshore near or just
to the west of Penobscot Bay. This is a slightly warmer solution for
us, so the main change with this forecast has been to pull back snow
even further below 1500 ft. Any cooling this evening will occur
shortly after sunset, as south flow will increase overnight, holding
temperatures steady or even warming them as we head into Monday
morning. As a result, lower elevations now look to remain in the mid
to even upper 30s much of tonight. Therefore, as precipitation
starts to spread eastward into our region late this evening, it will
primarily fall as rain in the valleys, perhaps mixing with some snow
at the onset. Snow will be the main precipitation type above 1500 ft
through the overnight hours, but even higher locations will start to
warm to above freezing Monday morning, allowing snow to transition
to rain. Still, even with this warmer solution, temperatures will be
very close to freezing, so just a degree or two warmer or colder
will potentially have a significant impact on snow levels and
amounts. At this point, anticipate locations below 2000 ft to change
over to all rain for at least a few hours Monday. Then, as the
secondary low shifts eastward into far northeastern ME and New
Brunswick, colder air will start to spill in as winds turn to the
west in the afternoon. Steadier precipitation will come to end,
becoming more showery and focused along the western slopes of the
northern Adirondacks/Greens while changing back over to snow. Some
enhancement off of Lake Ontario is also possible during the
transition period, though the main lake effect band should quickly
pivot to just south of our northern NY zones. This forecast
continues with the idea of little/no snow accumulation below 1500
ft, 1-3 inches 1500-2500 ft, and 3-5 inches at summit levels through
Monday evening. However, given the marginal temperatures, near
isothermal profiles, and our complex terrain, trends will need to be
monitored heading forward.

The other concern with this system will be the potential for gusty
winds. South/south winds today may be a little on the breezy side,
especially in the St Lawrence and Champlain Valleys due to
channeling. However, better chances arrive tonight and especially on
Monday. A strong SE 850 mb jet will develop on the front side of the
coastal low tonight as it deepens and lifts into the Gulf of Maine.
Mixing won`t be optimal overnight, so expect the core of this jet
will stay confined to summit level. However, once the low moves into
Maine and flow turns to the west, lapse rates will steepen due to
cold air advection. 850 mb winds won`t be quite as strong, but
better mixing means gusts of 30-35 mph will be possible Monday
afternoon/evening, especially on the eastern sides of the
Adirondacks/Greens.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 324 AM EST Sunday...A cold front traversing across the region
Monday will bring the widespread precipitation to an end, ushering
in some colder air. Scattered snow showers, primarily tied to higher
elevations, will continue after this surge of cooler air before
tapering off Monday night. A band of lake effect snow developing off
Lake Ontario will primarily impact areas south of the forecast area,
although some additional snow across southern St. Lawrence County
into portions of the Adirondacks will be possible. Additional QPF
amounts after the widespread precipitation will be fairly light,
generally only a few hundredths to about 0.15 of an inch across the
higher terrain where showers develop.

Overnight lows Monday night will be fairly seasonable, with
temperatures in the teens to upper 20s. Temperatures on Tuesday will
be blustery, with daytime highs generally in the 20s to near
freezing in the broad valleys. Brisk westerly winds will make it
feel even cooler, with apparent temperatures in the teens to single
digits across the high terrain. Low temperatures Tuesday night will
also be on the frigid side, with single digits to low 20s across the
region.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 324 AM EST Sunday...Broad cyclonic flow across the region will
continue to bring cool and unsettled weather into the beginning of
December, with shortwaves periodically pushing into the region. As
is often the case, confidence regarding the timing of these
shortwaves and associated showers is fairly low, so NBM guidance was
primarily used. Although the pattern will remain fairly active, it
will be fairly unimpactful with more nuisance showers throughout the
week. Temperatures will gradually moderate throughout the week,
warming from chilly mid 20s and low 30s on Wednesday up to
seasonable mid 30s to near 40 by Friday.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Through 12Z Monday...VFR conditions prevail across the region
this morning, and this will continue through at least 00z
Monday, though mid/high clouds will thicken through the day.
Widespread precipitation will move in from southwest to
northeast from 00z Monday onward, mainly rain at the valley
terminals. Higher elevation sites including KSLK, KMPV, and KEFK
will start out as snow, but could mix with rain late in the TAF
period. All sites to lower to at least MVFR between 00z and
06z, and remaining so thereafter. IFR visibility is likely in
any snow. South/southwest winds 5 to 10 kt through 00z Mon, with
brief gusts to 18 kt possible. Increasing low-level jet
thereafter will bring LLWS to all terminals overnight.

Outlook...

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

&&

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

&&

$$
SYNOPSIS...Hastings
NEAR TERM...Hastings
SHORT TERM...Kremer
LONG TERM...Kremer
AVIATION...Hastings