Pownal, Vermont Weather Forecast Discussion

340
FXUS61 KALY 232348
AFDALY
AREA FORECAST DISCUSSION
National Weather Service Albany NY
748 PM EDT Tue Sep 23 2025
.UPDATE...
Band of rain showers, some moderate in intensity, no expanding
east/northeast along the I-88 corridor and should reach near or
just south of the immediate Capital Region into the northern
Taconics and Berkshires within the next 1-2 hours. Highly
beneficial rainfall will occur where this band sets up. Farther
north, isolated/scattered showers across the upper Hudson Valley
will continue slowly moving south/southeast over the next 1-2
hours before weakening. Have adjusted PoPs for these 2 areas
accordingly reflecting latest radar trends.
&&
.SYNOPSIS...
Unsettled conditions will sustain isolated to scattered showers
across the region through tomorrow. Appreciable and much needed
rain is then anticipated Wednesday night through Thursday night
before drier weather gradually makes a return towards the end of
the week and into the weekend. Temperatures will remain a few
degrees above normal for much of the next seven days.
&&
.DISCUSSION...
Key Messages:
- Confidence continues to increase surrounding the potential
   for appreciable, much needed rainfall to amount across the
   region Wednesday night through Thursday night.
- Probabilities for at least 0.5" have increased to ~70-90%
   through Thursday night with probabilities for at least 1"
   remaining around 40-70%.
Discussion:
The shortwave that brought showers to the region this morning
has passed off to our north and east, allowing the spatial
extent of showers to largely decrease. However, still disturbed
upper-level flow and marginal instability with high PWATs across
the region has sustained isolated to widely scattered showers as
of this afternoon. Based on reflectivity on the KENX radar and
dry air intrusion seen on the latest scans of water vapor
imagery, much of this may be virga or light drizzle with little
to any additional accumulation to what already fell this
morning. However, tonight, as a cool, surface frontal boundary
begins to slide south through the region and interacts with a
developing surface cyclone to our south, showers will be
reinforced particularly for areas south of Albany. Some
lingering instability and decent omega intersecting the
moisture-laden column should aid in the development of some
locally moderate to heavier downpours especially in the
Southeast Catskills where upslope flow will help with both
ascent and moisture maintenance/reinforcement. Still, with as
dry as we have been over the past several weeks, any heavier
shower will only produce beneficial rain and no hydrological
issues. However, there is an expectation for widespread fog
development tonight so visibilities will be impacted. Exercise
caution on any and all travel as reductions could be rapid. Lows
tonight will fall to the low/mid 50s to low 60s.
The aforementioned boundary settles just to the south of the
region tomorrow morning, the area of surface low pressure
remaining draped along it. Aloft, heights ridge ever so slightly
as a broad surface high builds southward from Quebec. With the
better low-level convergence displaced to our south and ascent-
challenging subsidence spreading into the northern portion of
the area, most shower activity will be kept at bay tomorrow.
That is, coverage will be even more limited than today,
especially with limited instability given extensive cloud cover.
Highs will be in the mid/upper 60s to mid 70s.
As in previous forecast iterations, the primary focus of the
next seven days is attributed to Wednesday night through
Thursday night. As the weak ridging aloft shifts east atop the
weakening, eastward-shifting anticyclone to our north, heights
begin to fall once again ahead of a deepening closed low located
over the western Great Lakes. Beneath the forward flank of the
trough extending south and west from this low, a surface cyclone
will begin to take shape and traverse the Ohio Valley on its
northeast trajectory into the eastern Great Lakes. Rain will
therefore begin to spread into the region from southwest to
northeast Wednesday night courtesy of cyclonic vorticity
advection and increasing isentropic lift as the previously
stalled boundary lifts northward as a warm front along with the
advancing low. Minimum temperatures Wednesday night will be in
the low/mid 50s to low 60s.
Rain will continue through Thursday, becoming potentially
moderate to locally heavy at times as a direct moisture fetch
develops off the Gulf along the leading edge of the trough and
instability increases with elevated dewpoints across the region
within the surface cyclone`s warm sector. Plenty of shear is
also noted across the region, especially for areas within and
south of Albany, which could allow for some more organized
convection to develop in the afternoon Thursday. However, this
is a bit uncertain given the likely limited instability, but
something to watch as SPC placed these areas into a Marginal
Risk for Severe Weather. The primary hazard will be strong to
locally damaging wind gusts given the favored soundings for
precipitation loading and potentially rapid cooling within the
column due to heavier rainfall rates. Highs Thursday will be in
the low/mid 60s to low/mid 70s.
By Thursday night, the previous shield of rain will gradually
begin to erode, becoming an area of showers as the
aforementioned closed low weakens into an open wave upon its
entrance into the eastern Great Lakes. Showers will persist into
Friday morning in association with the passage of the cold
front, but coverage will continue to decrease before completely
coming to an end by Friday afternoon/evening. When all is said
and done, QPF looks to range from about 1" to locally higher
amounts of 1.75" across the region. Lows Thursday night will be
in the low/mid 50s to low 60s. General consensus then indicates
a return to drier conditions Friday night into Saturday as flow
aloft becomes zonal. However, a few lingering, lake-enhanced
showers in the higher terrain of the Southwest Adirondacks will
remain possible through Saturday resulting from a weak shortwave
rotating through the region. But confidence is not high in this
element of the forecast as few guidance members actually show
this. Highs Friday will be in the upper 60s to upper 70s with
lows Friday night in the upper 40s to upper 50s. Highs Saturday
and lows Saturday night will be similar to those of Friday and
Friday night.
Sunday looks to be primarily dry, though medium to long-range
guidance is struggling to come to a consensus about a couple of
nearby disturbances that could bring some light, scattered
showers. Regardless, high pressure will begin building in once
again Sunday night, overspreading the region Monday and
reinforcing regionwide dry conditions for the beginning of the
new work week. High temperatures Sunday will be in the upper 60s
to upper 70s and possibly near 80 for some in the lower Mid-
Hudson Valley. Lows Sunday night will be in the mid/upper 40s
to low 50s. Highs Monday will be in the upper 60s to upper 70s
with lows falling to the low/mid 40s to low 50s.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Through 00Z/Thu, a few showers may impact KGFL over the next 1-2
hours, with additional showers impacting KALB/KPSF through
around midnight. Periods of MVFR Vsbys/Cigs may occur within
some of these showers. Otherwise, VFR conditions early this
evening should trend to MVFR/IFR after midnight, mainly for
Cigs, with pockets of LIFR possible. MVFR/IFR conditions should
linger through most of Wednesday mainly for Cigs. Additional
showers are expected to develop mid morning Wednesday around
KALB/KPSF, eventually shifting north to KGFL in the afternoon.
In between any showers, there could be areas of drizzle as well
during Wednesday. Light/variable winds overnight will become
northeast to east at generally less than 5 KT Wednesday.
Outlook...
Wednesday Night: High Operational Impact. Likely SHRA...TSRA.
Thursday: High Operational Impact. Definite SHRA...TSRA.
Thursday Night: High Operational Impact. Likely SHRA.
Friday: Moderate Operational Impact. Chance of SHRA.
Friday Night: Low Operational Impact. Slight Chance of SHRA.
Saturday: Low Operational Impact. Slight Chance of SHRA.
Saturday Night: Low Operational Impact. Slight Chance of SHRA.
Sunday: Low Operational Impact. NO SIG WX.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
UPDATE...KL
SYNOPSIS...Gant
DISCUSSION...Gant
AVIATION...KL

NWS ALY Office Area Forecast Discussion