Brattleboro, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

725
FXUS61 KALY 220557
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1257 AM EST Sat Feb 22 2025

.SYNOPSIS...
Lots of sun today albeit breezy and chilly. Temperatures
gradually trend milder this weekend with some lake effect snow
showers for the western Adirondacks Saturday night into Sunday.
Temperatures continue to trend milder through early next week with a
few weak clipper type disturbances that may bring a mix of rain and
snow showers.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
.UPDATE...As of 12:55 AM EST...Flurries continue across portions
of the Catskills and Capital District, as well as the western
Mohawk Valley. 00z KALY sounding shows moisture trapped beneath
a low-level inversion. This is also leading to some lake effect
clouds extending from the Mohawk Valley through the Catskills
into the Berkshires as well, which have kept temperatures and
dew points locally higher in these areas. Also made some
adjustments to temperatures, as portions of the ADKs are already
below zero (coldest spot is -4F at Old Forge), with temperatures
also running on the cold side across portions of the upper
Hudson Valley where there is clear skies and light winds. Mid
Hudson Valley has also cleared out, but winds remain light here,
and have prevented temperatures from falling as quickly.
However, as a ridge of high pressure builds in from the west, we
should see winds diminish and temperatures continue to drop for
areas that remain cloud-free. An approaching upper shortwave
should also spread some more high clouds into the region towards
the pre-dawn hours. All that said, previous forecast for a
chilly night still remains on track with more details in the
previous discussion below...

.Previous...We stay cold into tonight. While initially clear
skies and a decent snow pack will support effective radiational
cooling, winds will remain a bit breezy through about Midnight
before turning light/variable. Once the winds turn light, wind
shifts to be more westerly in response to the building ridge
that flattens out as it shifts east of Lake Ontario. Winds
becoming more westerly will help usher in more lake moisture and
thus increase cloud coverage overnight. So, overnight lows will
be a bit tricky as discussed in the previous discussion
depending upon how quickly winds weaken and clouds return.
Either way, still expecting quite the chilly night as
probabilistic temperatures show 40 - 90% chance from I-90
northward for temperatures to fall below 10 degrees by 7 AM
Saturday morning. Coldest temperatures expected in the Upper
Hudson Valley where a few sub-zero temperatures are expected.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
A generally pleasant weekend ahead for most of eastern NY and
western New England with temperatures finally trending above
freezing each afternoon. Early clouds tomorrow give way to
partly to mostly sunny skies as a shortwave tracking to our
east supports subsidence in its wake. With the mid and upper
level flow shifting to the west and southwest, the return flow
will support temperatures finally warming towards to a few
degrees above freezing. Mildest temperatures in the mid-Hudson
Valley in NW CT where mid-30s are expected. Luckily the winds
will be lighter tomorrow. Westerly winds continuing Saturday
night combined with an incoming weak shortwave impulse will
support a lake effect response with snow showers extending into
the western Adirondacks. Some upslope snow possible for southern
VT. Moisture is lacking only only expecting up to an inch of new
snow. Otherwise, skies turn cloudy and temperatures fall into
the teens and 20s throughout the region.

A boundary weakens and stall over the area on Sunday and with
westerly/confluent flow remaining in place, expecting mostly
cloudy skies. Despite the clouds, westerly flow will still
advect in a milder air mass and high temperatures will rise into
the mid to upper 30s in valley areas. Higher terrain and valley
areas rise into the 20s with light snow showers in the western
Adirondacks gradually weakening through the afternoon. Clouds
continue overnight with our stalled boundary lifting northward
as a warm front. A few light snow showers remain possible, even
outside of the higher terrain, in response to increasing warm
air advection. Overall QPF amounts remain light and thus limited
POPs to slight chance mainly for southern Adirondacks but
future forecast updates may see POPs expand into valley areas
depending on trends.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Key Message:

- Temperatures trend above normal next week with a series of
  clipper systems bringing periods of rain and snow showers.

Discussion:

An active northern stream pattern will set up next week with
multiple shortwaves passing through the Northeast. Deterministic
and ensemble guidance continue to show at least three different
potent shortwaves that develop into quick clipper-type
disturbances mainly during the Monday-Monday Night, Tuesday-
Wednesday and Thursday-Friday time frame. Daytime high temperatures
in late February are usually in the mid to upper 30s but with
westerly to southwesterly flow persisting aloft, temperatures
look to trend above normal reaching into the 30s to even 40s in
valley areas with 30s in the higher terrain. Overnight lows
generally in the 20s and 30s. These temperatures would generally
favor valley rain and higher elevation snow depending on the
exact track and timing of each disturbance. Overall moisture
is still lacking as these northern stream clippers originate in
western/central Canada. In fact, probabilistic guidance shows
under 10% chance for QPF amounts in any 12 hour period Monday
through Wed night to reach or exceed 0.25 inch.

By Thursday - Friday, ensemble and deterministic guidance still
indicates a more amplified trough developing over the Midwest/TN
Valley system with potential for it to tap in Gulf and/or
western Atlantic moisture. However, latest trends show
uncertainty on when/if the trough will eventually amplify into
the Southeast and any phasing potential with northern stream
shortwaves. Earlier guidance suggested the potential for a
coastal low for the end of the week but latest trends have
delayed the trough amplification and any developing coastal low
tracks off shore. Still something to monitor as there is plenty
of uncertainty with the overall flow pattern and how the
shortwaves earlier in the week modify the pattern. Probabilistic
guidance still shows probabilities for 0.25 inch or more of QPF
trending upwards to 10-25% by the end of the week.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Through 06z/Sun...Lake-effect stratocu clouds remain in place at
KALB/KPSF but there are signs of clouds beginning to finally
diminish per latest satellite imagery. As a result, mainly VFR
conditions are expected at KALB/KPSF but included a TEMPO for a
couple more hours at KPSF for any lingering MVFR cigs before
coverage reduces to FEW-SCT. KGFL/KPOU will remain VFR through the
rest of the night with nearly SKC conditions.

Saturday will feature patchy low clouds redeveloping and also
passing cirrus clouds. Cigs may return to the MVFR range for a time
at KALB/KGFL/KPSF later Saturday morning into the afternoon, as lake
moisture remains trapped under an inversion, before lifting back to
VFR. KPOU should remain VFR through Saturday evening.

Wind will gradually diminish to 4-8 kt overnight at KALB/KPSF with
light and variable wind continuing at KGFL/KPOU. Wind will become
south to southwesterly Saturday morning and continue through
Saturday evening.

Outlook...

Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: Moderate Operational Impact. Chance of SHRA.
Monday Night: Moderate Operational Impact. Chance of SHRA.
Tuesday: Moderate Operational Impact. Chance of SHRA.
Tuesday Night: Low Operational Impact. Slight Chance of SHRA.
Wednesday: No Operational Impact. NO SIG WX.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Speciale
NEAR TERM...Gant/Main/Speciale
SHORT TERM...Speciale
LONG TERM...Rathbun/Speciale
AVIATION...Main