718
FXUS61 KBTV 041201
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
801 AM EDT Thu Sep 4 2025

.SYNOPSIS...
A cold front will move through from west to east today and tonight,
bringing a line of showers and potentially a few embedded
thunderstorms. Ahead of it, strong southerly winds will blow between
15 to 25 mph, with locally higher gusts in the Champlain Valley and
far northern Adirondacks. The winds, combined with low relative
humidity this afternoon, will cause fire weather concerns. Some
unsettled weather remains through the weekend before cooler and
drier air arrives for next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 302 AM EDT Thursday...Much of the region saw the boundary layer
decouple for the first part of the night, but as a southerly low
level jet gradually moves overhead, areas will slowly begin to mix.
This will cause temperatures to hold steady or rise in the second
half of the night outside the most protected valleys. BTV rose from
60 to 68 degrees this morning so far. It may prevent BTV from seeing
ten nights in a row in the 50s. These southerly winds will continue
to strengthen during the day, and despite a warm air advection
profile, there will not be much of an inversion so winds will mix
very efficiently. Gusts in the 15-25 mph range are expected in most
places, but channeling in the Champlain Valley and downsloping in
the far northern Adirondacks should cause them to reach up to 40 mph
in localized areas. Relative humidities will drop far due to a dry
airmass and the aforementioned deep mixing, so combined with the
strong winds, there are fire weather concerns. See the fire weather
discussion for more details. A line of showers will move through
this afternoon and evening associated with a cold front. Some
embedded thunderstorms are possible, particularly over northern New
York where a brief severe storm is possible. It is a low CAPE high
shear setup, but with weakening synoptic forcing as the front moves
through, the shear could be too strong for any severe development.
However, with the strong low level jet overhead, it will not take
much to mix some stronger winds to the surface so gusty showers are
still expected. The cold front passes to the east tonight, and the
showers will gradually leave Vermont. Tomorrow should be mostly dry
with the region caught between two fronts, but a couple isolated
showers are still possible. Another low level jet will enter the
region tomorrow afternoon, but it looks to be a little weaker and
more southwesterly. However, gusty winds are expected again.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 302 AM EDT Thursday...Another front will be approaching from
the west Friday night, attached to a deep area of low pressure far
to the north by James Bay. Have increased winds during this period,
especially in the mountains. Low level southwesterly flow strengthen
out ahead of the front, and forecast soundings showing a jet
lowering into the 850 - 925 millibar layer with winds peaking during
the early morning hours in the 40 to 50 MPH at our higher summits,
while a combination of nocturnal stability and rain in the St.
Lawrence Valley will greatly limit gustiness at lower elevations
during this period. With low chances of rain in the Champlain
Valley, south winds overnight will keep temperatures unseasonably
mild, only falling slowly into the upper 60s for much of the night,
until winds relax towards daybreak. Most likely temperatures
elsewhere overnight will dip into the low 60s in Vermont and mid to
upper 50s in the Adirondacks and St. Lawrence Valley on the cool
side of a strengthening thermal gradient.

An area of frontogenesis will be stretched out from southwest to
northeast, roughly from northern New York into northwestern Vermont
Saturday morning where a narrow zone of deep moisture and associated
convergence should promote increasing coverage of showers. This area
will be where heaviest rainfall will fall through the day,
especially as pockets of instability develop along with anomalous
precipitable water near 1.5". There doesn`t look to be much
instability to work with and it will be largely elevated, so would
expect relatively gentle rainfall rates under 0.5"/hour and in most
cases closer to 0.1"/hour. The zone of showers will gradually shift
eastward during the day, with it perhaps stalling out enough to help
a portion of Vermont see locally heavier rainfall. Meanwhile, enough
heating in southeastern Vermont will occur to support surface-based
instability, with most likely values 500 - 750 J/kg. Much greater
instability is favored farther south and east of the region where a
severe weather threat will probably be present in southern New
England, but the overlap of instability and the moisture convergence
over southern portions of Vermont suggest more efficient rainfall
Saturday afternoon/evening with any thunderstorms. From Friday night
through Saturday night, current rainfall amounts are expected to be
mainly in the range of 0.67" to 1" in Vermont, 0.4" to 0.75" in the
Adirondacks and western Champlain Valley, and 0.1 to 0.4" in the St.
Lawrence Valley.

Unsurprisingly with shifts in the position of the front during the
day Saturday, high temperatures are rather uncertain, especially in
the middle of our region. The spread in far southern/eastern
portions of Vermont is a bit lower as this area seems likely to warm
up into the 80s; similarly, much of northern New York is primed to
be sharply cooler than recent days with highs in the 60s. Low level
cooling should infiltrate all of Vermont by late Saturday night, so
low temperatures should be somewhat more predictable in the mid 40s
to low 50s for most locations.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 302 AM EDT Thursday...On Sunday some lake-effect rain showers
are expected downwind of Lake Ontario. Its water temperature is
still warm (about 20 Celsius) and seasonably cool 850 millibar
temperatures about 4 degrees Celsius and southwesterly low level
flow will tend to bring showers mainly into southern St. Lawrence
County with higher confidence than into the Adirondacks at this
time. Some deterministic model guidance is showing a well-timed
shortwave trough digging over the eastern Great Lakes, supplying
stronger southwesterly flow that could help generate more widespread
showers enhanced by orographic lift. As we get into the shorter
range the predictability of the forcing and higher PoPs over a
larger area can be expected, potentially extending into the northern
Green Mountains.

Monday through Wednesday, yet again, are probably going to be dry as
ridging builds in from the west. Temperatures trend lower for
Monday, which will probably be the coolest day of the next seven.
Ensemble mean 850 millibar temperatures of only 2 to 4 degrees C,
assuming dry adiabatic mixing, would lead to highs in the low to mid
60s, with our warmest spots topping out in the upper 60s. With a
cool and dry air mass in place, we`ll have to consider the
possibility of frost if high pressure builds in Monday night to
support calm winds and clear skies. Right now, the surface ridge
expected to move over the region does not appear expansive enough to
say it will be a lock, but it`s something to look out for,
especially in the Adirondacks. Generally temperatures Monday and
Monday night will be about 10 degrees below normal. A moderating
trend is probable over the following couple of days as flow becomes
southwesterly on Tuesday, while a weak frontal passage may occur on
Wednesday tempering the warm up with only very low chances for rain
at this time.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Through 12Z Friday...VFR conditions will continue into through
at least 18Z. Thereafter, clusters of showers will approach from
the west, reaching MSS most likely between 20 and 21Z, SLK
between 22 and 23Z, between 23Z and 00Z at PBG, and after 00Z at
Vermont sites. An embedded thunderstorm or two is possible,
mainly over northern New York, with relatively high probability
near 30% at MSS. Ceilings during and behind the front may
briefly drop to MVFR, particularly over the northern New York
terminals. The rain may be briefly heavy enough to reduce
visibilities to MVFR or even IFR, with the highest probabilities
at MSS and SLK. Southerly winds will increase during the rest
of the night and into the day, with gusts in the 10-20 kt range
expected for most areas. BTV and PBG could see brief gusts up
to 30 kts. Winds will stay elevated until late evening. LLWS
will develop for a period of time in the afternoon and evening.

Outlook...

Friday: Mainly VFR, with local MVFR possible. NO SIG WX.
Friday Night: Mainly VFR, with local MVFR possible. Chance SHRA.
Saturday: Mainly VFR, with areas MVFR possible. Likely SHRA,
Slight chance TSRA.
Saturday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: Mainly VFR, with local MVFR possible. NO SIG WX.

&&

.FIRE WEATHER...
Fire weather concerns will be heightened today, with minimum
relative humidity values in the 25-35% range, with the lowest
numbers in the Champlain and Connecticut River Valleys. Winds
ahead of an approaching cold front will be gusty up to 35 mph in
the north to south oriented valleys and the northern
Adirondacks. Elsewhere, they will gust in the 15-25 mph range.
Recent dryness has dried fine fuels and has led to a moderate
drought in some areas. A Special Weather Statement for increased
fire weather potential will be in effect for today for all of
Vermont and portions of northern New York. Wetting rain from
showers and embedded thunderstorms will arrive in the St.
Lawrence Valley early this afternoon and by tonight in Vermont.
Winds will begin to diminish with the onset of precipitation.
Lingering shower chances continue into the weekend. Fire weather
concerns will decrease with the wetting rain and decreasing
winds.

&&

.MARINE...
Southerly winds will continue to increase and they should reach 15-
25 KTs in the latter part of the night and into the morning. Winds
should increase a bit more during the day, with gusts between 30-35
KTs possible in the late afternoon and early evening. They could be
briefly higher as a line of showers moves through in the evening. An
embedded thunderstorm is possible as well. Winds drop pretty quickly
tonight and they should be around and below 10 KTs by late in the
night. The break in the strong winds will be short lived as they
increase into the 15-20 KT range tomorrow afternoon, with gusts
again possible in the 25-30 KT range. They will then gradually
decrease late tomorrow night and into Saturday, eventually dropping
into the 5-10 KT range. Winds will generally remain southerly until
they shift westerly on Saturday.

&&

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

&&

$$
SYNOPSIS...Myskowski
NEAR TERM...Myskowski
SHORT TERM...Kutikoff
LONG TERM...Kutikoff
AVIATION...Kutikoff/Myskowski
FIRE WEATHER...BTV
MARINE...BTV