Stratton, Vermont Weather Forecast Discussion

640
FXUS61 KALY 161028
AFDALY
AREA FORECAST DISCUSSION
National Weather Service Albany NY
628 AM EDT Tue Sep 16 2025
.SYNOPSIS...
Above normal temperatures continue through Friday with a
weakening coastal low slowly approaching tonight into Wednesday
resulting a few light showers mainly south of I-90. Then, a
moisture starved cold front on Friday ushers in breezy winds
followed by cooler temperatures for Saturday. Temperatures trend
warmer for the start of the new work week.
&&
.DISCUSSION...
Our Rex Block begins to breakdown today as our ~590dam upper
level anticyclone weakens as it shifts eastward out of the Great
Lakes. This occurs while our vertically stacked coastal low
currently seen on water vapor imagery off the mid-Atlantic coast
slowly presses northward. Thus, initial sunshine today will
become filtered through increasing cirrus clouds that gradually
expand from south to north ahead of the approaching coastal
low. Temperatures today once again rise above normal as deep
boundary layer mixing in a dry environment with 850hPa
isotherms +10C to +13C and insolation supports temperatures in
the mid to upper 70s with even low 80s in the Upper Hudson
Valley where more sunshine will likely occur. Cirrus clouds
expands and thickens tonight as our coastal continues its slow
approach.
As mid and upper level moisture increases, isolated to widely
scattered showers on the northern periphery of the low start to
impinge upon the mid-Hudson Valley and NW CT during the pre-dawn
hours (09 - 12 UTC) and we continue to show slight chance POPs
here which matches with the ECMWF ensemble and NBM
probabilities. Previous model runs suggested the incoming
coastal low would weaken enough during its approach that slight
chance and low end chance POPs would mainly be confined to our
far southern zones. While the highest confidence in measurable
showers remains over southern zones (20-35%), latest trends
suggest up to a 15% chance that isolated showers expand as far
north as the I-90 corridor given that the low`s 500hPa
circulation remains closed through 00 Thurs. Otherwise,
Wednesday will feature cloudier skies, especially from I-90
southward with more filtered sun to the north. Thus, high
temperatures will fall a few degrees short compared to the days
leading up to it with 70-80% chance that temperatures exceed 75
degrees north of I-90 with just 25-50% chance to the south where
clouds will be thicker. Total QPF amounts remain low and will
not put a dent in the ongoing rainfall deficit as there is just
a 20-40% chance that total rainfall exceeds a tenth in the mid-
Hudson Valley and NW CT and under 10% closer to I-90.
Rain showers diminish in coverage Wed night into early Thursday
as the coastal low`s 500hPa circulation opens up and exits into
New England. Early clouds give way to increasing sun on
Thursday as weak high pressure builds overhead. Slightly breezy
westerly winds behind our departing coastal low enhances
boundary layer mixing and supports above normal temperatures
once again. In fact, there is a 70-90% chance that highs exceed
80 degrees in valley areas but nearly 0% chance to exceed 85.
Thursday night. A more potent yet moisture starved cold front
then marches south and eastward out of Canada late Thurs night
into early Friday morning. A tightening pressure gradient in
the wake of the boundary will likely support breezy winds on
Friday with northwest flow ushering in a much drier air mass
(PWATs near 0.5"). Thus, we trended dew points downwards using
the NBM 10th percentile to show values falling into 30s/40s.
Between the dry air mass (RH values 30-45%), recent stretch of
dry weather, and slightly breezy winds, we will monitor the
potential for enhanced fire spread on Friday. A ~1030hPa
Canadian sfc high and upper level ridging build into the
Northeast for Saturday, supporting abundant sunshine and
ushering in a fall-like air mass. Morning lows on Saturday turn
quite chilly with a 50 - 75% chance for lows in the southern and
western Adirondacks to fall to 35 degree or lower so we will
need to monitor frost potential. High pressure slides into New
England for Sunday, promoting a southwest return flow and
allowing tempertures to trend warmer for the new work week.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Through 12z/Wed...Fog at KGFL/KPSF will lift by 13z/Tue;
otherwise, VFR conditions are expected for much of the upcoming
TAF period with some mid and high clouds around as a coastal
low pressure system slowly lifts northward. With the additional
clouds tonight, confidence on fog development is low so did not
include any mention at this time. Wind will become variable or
southeasterly at 5 kt today, then trend light to calm again
tonight.
Outlook...
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Speciale
DISCUSSION...Speciale
AVIATION...Rathbun

NWS ALY Office Area Forecast Discussion