029
FXUS61 KBTV 231121
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
721 AM EDT Sat Aug 23 2025

.SYNOPSIS...
A warm late August day in the 80s is expected. Increasing winds and
dry humidity is expected across Vermont and northern New York.
Beneficial rain remains on track as a slow moving cold front shifts
east tonight through Monday. Showers and thunderstorms could produce
a few areas of locally heavy rain. Gusty south winds ahead of the
front and in stronger shower activity could produce gusts of 30 to
35 mph, mainly in the Champlain Valley and north facing slopes of
the Adirondacks. Cooler air returns for the midweek, and a few
showers will remain possible as weak disturbances will periodically
pass nearby.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 158 AM EDT Saturday...Another warm late August day will unfold
as high pressure slides east. Building pressure gradients will add
some breezes, with afternoon mixing allowing gusts of 20 to 25 mph
to develop today. As temperatures warm well into the 80s today, our
relative humidity values will range between 35 and 45 percent for
much of the region, locally down to 30 percent. Developing drought
could pose some fire weather concerns. Otherwise, it`ll be a fairly
comfortable day given the low humidity and the breezy conditions.
Plenty of sun expected today, but clouds will increase from the west
as a cold front approaches. A few stray showers may track into the
St. Lawrence Valley during the evening.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
As of 158 AM EDT Saturday...Beneficial rain is on the way, and the
range of probabilistic guidance has indicated increasing confidence
on some higher rainfall amounts again after backing off some
yesterday. There remains little change from previous discussions.
Deep channeled flow will set up with strengthening southwesterly
flow not totally paralleling a slow, stretched out frontal boundary.
A combination of embedded shortwaves, moisture advection, and
diurnally driven instability along this slow moving front will
produce several rounds of showers and a few thunderstorms. Enough
forward motion of the front should prevent an overabundance of rain.

Gusty conditions are expected as flow accelerates between tightening
pressure gradients and conditions remain favorable for mixing. A
lingering warm nose behind the departing ridge will result in
downslope gusts and efficient channeling between the Adirondacks and
Greens. Northern slopes of the Adirondacks along Route 11 and much
of the northern Champlain Valley will likely observe increasing
winds overnight, likely maximizing around dawn around 30 to 35 mph
before gradually tapering off. Dealing with gusty winds is another
sign we`re starting to transition out of summer here.

For thunderstorms on Sunday, there could be a couple rounds
associated with a prefrontal trough lingering across Vermont during
the morning hours and then the actual front approaching the St.
Lawrence Valley late in the evening. Bulk shear of 35 to 45 knots is
favorable for stronger thunderstorms, but forecast CAPE values
remain somewhat marginal around 500-1000 J/kg. Although we have a
frontal boundary, convergence along it is not great, and the air
mass will be contaminated with clouds and morning showers. So it`s
not an ideal set up for severe weather, but there could be a
stronger storm or two capable of gusty winds given good low-level
lapse rates and fast flow.

For Monday, the frontal boundary will slip into Vermont. The front
will slow further as a coastal low tracks along the US East Coast.
The upper vort from James Bay will be shifting eastwards and
convergence along the frontal boundary will become better defined as
the coastal low imparts some southeasterly component across interior
New England. Precipitation should blossom across Vermont on Monday
with convective elements due to 250-750 J/kg of CAPE likely. Again,
we`ll have 35 to 45 knots of shear, but it appears that lapse rates
will be back to their typical poor values with hints of warming
aloft across eastern Vermont that should preclude severe weather.
Between Sunday and Monday`s precipitation, about 0.20-0.75" is
expected for northern New York and about 0.50-1.00" is expected for
Vermont. Locally higher amounts in thunderstorms of 1.25-1.75"
appear reasonable. This will be some much needed rain. Flash flood
guidance values are very high due to lack of rain, and so we`re
expecting this to simply do the region good.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 158 AM EDT Saturday...A deep upper level trough will continue
to meander across the region next week,bringing cooler conditions.
Chances for diurnally driven showers will continue to linger through
much of the week as the area remains under broad cyclonic flow.
Temperatures will be on the cooler side during this time frame with
abundant cloud cover and northwesterly flow, with high temperatures
on the mid 60s to low 70s for both Tuesday and Wednesday with
overnight lows dropping into the 40s to low 50s. A brief period of
ridging will be possible towards the end of next week, although
there is still low confidence in the overall pattern evolution at
this time.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Through 12Z Sunday...VFR conditions will prevail throughout the
forecast period. Cloud cover will gradually increase throughout the
day into the evening as the next chances for precipitation approach
the region, but ceilings will remain above VFR thresholds. Main
concern to aviators during this time frame will be winds and
potential for some LLWS. Light and variable winds this morning will
gradually increase from the south/southwest by the afternoon, with
gusts around 20 knots or so possible after 16Z. Heading into the
evening and overnight hours, these gusty winds are expected to
continue, especially in the Champlain Valley where KBTV may see
gusts up to 30 knots due to the channeled southerly flow.

Outlook...

Sunday: VFR. Chance SHRA, Chance TSRA.
Sunday Night: Mainly VFR, with local IFR possible. Definite SHRA,
Chance TSRA.
Monday: Mainly VFR, with local IFR possible. Likely SHRA, Slight
chance TSRA.
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Chance SHRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Wednesday: Mainly VFR, with local MVFR possible. NO SIG WX.

&&

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

&&

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