932
FXUS61 KBTV 031837
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
237 PM EDT Wed Sep 3 2025

.SYNOPSIS...
Terrain-driven showers and thunderstorms this afternoon will
dissipate by this evening with mainly clearing skies. A cold
front will approach the region tomorrow with showers,
thunderstorms, and increasing gusty winds up to 35 mph at
times. Deep mixing tomorrow will lead to unusually low relative
humidity values which will lead to heightened fire weather
concerns through tomorrow afternoon. Unsettled weather remains
through the weekend with chances of rain each day before cooler
and drier air arrives for next week.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
As of 227 PM EDT Wednesday...A weak shortwave is passing through the
region along a broader trough associated with a deepening Great
Lakes upper low. A few isolated showers and thunderstorms have
developed along the higher terrain from some enhanced orographic
lift. Most of the these showers will stay confined to the higher
terrain and drift northeastward, but should weaken as they move off
the terrain. A few locations may see a few hundreths of an inch of
precipitation, but most of the area will remain dry through this
evening. Other than the terrain-driven rain, most of the region will
continue to enjoy a mostly sunny day with temperatures in the upper
70s to near 80 and low humidity values. Deep vertical mixing to
nearly 750mb has dropped relative humidity values to near critical
fire weather thresholds in the 25-35% range. While fire weather
concerns today are low due to low winds, the persistent dryness will
lead to heightened fire weather concerns heading into tomorrow; see
our fire weather discussion. Overnight lows tonight should
efficiently radiate out across the deeper valleys with values in the
mid to upper 40s in the terrain and in the mid 50s in the valleys.
Winds will generally increase overnight ahead of the approaching
main trough as the pressure gradient tightens. While fog chances are
low given the increased winds, locations seeing rain today, and in
the wider Connecticut River Valley, some patchy fog is possible.

As the long-wave trough moves closer tomorrow, winds ahead of a cold
front will rapidly increase by Thursday morning. Deep mixing up to
700mb with super adiabatic lapse rates will help pull top of the
mixed layer winds around 45 mph, associated with a low-level jet,
towards the surface. Surface winds, particularly in the north-south
oriented valleys, on Lake Champlain, and in the downsloping favored
locations in the Adirondacks could see wind gusts up to 35 mph at
times tomorrow afternoon. Elsewhere winds could likely reach to 15-
25 mph. Sustained winds will likely be in the 15 to 25 mph range, so
a Lake Wind Advisory on Lake Champlain is likely needed as early as
7 AM tomorrow morning. In addition to the winds, deep mixing will
lead to further drying of the surface with relative humidity values
as low as 25% possible. This coupled with low to zero last 7 days
precipitation amounts, will create high fire weather potential
tomorrow afternoon. A Special Weather Statement will be issued for
the State of Vermont and portions of northern New York for this
increased fire weather concern.

The cold front, in the form of a broken line of showers, will move
into the St. Lawrence Valley by early Thursday morning which should
quickly decrease gusty winds with the arrival of the rain. Any t
Thunderstorm activity will likely be embedded in the showers, though
instability fairly low under 500 J/kg. However, shear will be 40-
50kts which could lead to some enhanced winds in any thunderstorms.
Furthermore, these showers will be high based with LCLs around 10kft
which could contribute to the gusty winds and potential for dry
thunderstorms as evaporative cooling takes place. The front will
race across northern New York and reach Vermont by Thursday night.
Precipitation amounts through Friday morning will be 0.5-0.8" of
rain across northern New York, and 0.4 to 0.25 inches from west to
east in Vermont. Locally higher amounts are possible under any
thunderstorms.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 227 PM EDT Wednesday...A cold front will continue to track
across eastern Vermont during the day Friday with decreasing
precipitation chances into Friday afternoon. As the center of the
system over the Great Lakes evolves and moves closer to the area, a
few gaps in the precipitation look likely Friday afternoon and
evening, however, cloud cover looks to remain abundant. Temperatures
will generally be a degree or two lower than Thursday with the
rainfall and cloud cover. Winds will continue to be from the south
and on the breezy side. Channeling effects in the Champlain Valley
and on the mountain summits will keep winds around 10 to 20 mph, and
20 to 30 mph, respectively, Friday afternoon. Winds should weaken by
Friday afternoon, with lows Friday night around 60 in Vermont, and
around 50 in northern New York. Reinforced moisture from the south
in association with another shortwave Friday night into early
Saturday morning will bring additional chances of precipitation to
the higher terrain.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 130 PM EDT Wednesday...Confidence continues to increase
for a wetting rainfall event from the eastern Dacks into most of
VT on Saturday associated with deepening mid/upper lvl trof and
secondary cold frnt. Synoptic scale lift wl be enhanced acrs VT
associated with right rear quadrant of anticyclonic curved jet
of 100 to 140 knots located over southern Canada, while low
level convergence is maximized near the slow moving boundary. In
addition, approaching mid/upper lvl trof and associated height
falls/embedded s/w energy wl enhance synoptic scale ascent to
support a wetting rainfall event acrs the eastern Dacks into
most of VT. Still some spread on heaviest axis of precip, but
greatest probability of >0.50" qpf is 60 to 90% from the dacks
into VT and near 50% probability of >1.0" qpf per the NBM
output. Given the increasing confidence and relatively good
agreement in the models, I have increased pops into the 60 to
80% range for Saturday, which is 10 to 30% above the latest NBM
guidance. Have noted a sliver of instability ahead of
approaching boundary where sfc based CAPE values are btwn
800-1200 J/kg over southern cwa, while 0 to 6 km shear is 45 to
60 knots. There is a conditional threat for a few strong to
severe storms on Sat acrs southern sections, if sfc
heating/instability can develop, given approaching height falls
with very strong mid/upper lvl trof. Potential for lake
enhanced/trrn induced showers looks to linger into Sat night and
Sunday, given the mid/upper lvl trof axis is still to our west
and we remain under cyclonic west/southwest upslope flow with
moderate llvl caa. Have bumped pops upward downwind of Lake
Ontario/Dacks during this time frame. Eventually strong high
pres builds into our cwa by Monday with clearing skies and
comfortable temps. These conditions wl prevail for most of next
week with nocturnal valley fog likely, along with some patchy
frost possible at SLK/NEK on Mon/Tues mornings, as latest
guidance supports lows in the l/m 30s coldest locations with
upper 40s near Lake Champlain. Highs generally in the 60s to
near 70F.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Thursday...VFR conditions currently at all taf
sites with widely scattered showers/storms mostly over the
terrain. However, a single cell is in the vicinity of PBG so
have mention VCTS, given the recent lightning activity for
another hour. Otherwise, VFR prevails into the overnight hours
and given developing 300 to 600 feet above ground level winds
increasing 15 to 20 knots after 06z, feel the potential for IFR
or lower in fog/mist is less 15%, so have not mention in any
tafs attm. A potential exception would be if a shower occurs
over a taf site this aftn, then the fog potential would
increase, especially MPV/SLK. Gusty south/southwest winds
develop 10 to 20 knots with gusts 20 to 30 knots on Thursday
with some localized wind shear/turbulence possible.

Outlook...

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

&&

.FIRE WEATHER...
Tomorrow, fire weather concerns will be heightened with minimum
relative humidity values in the 25-35% range, particularly in
the Champlain and Connecticut River Valleys. Winds ahead of an
approaching cold front will be gusty up to 35 mph at times in
the north to south oriented valleys beginning early Thursday
morning. Recent dryness has led to moderate drought in portions
of northern New York and central and northern Vermont which
will further contribute to near critical fire weather concerns
throughout tomorrow. A Special Weather Statement for increased
fire weather potential will be in effect for tomorrow 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 Thursday afternoon and by Thursday night
in Vermont with the arrival of a cold front. Winds will abate
with the onset of precipitation. Lingering shower chances
continue into the weekend. Fire weather concerns will decrease
with the wetting rain and decreasing winds beyond Thursday
night.

&&

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

&&

$$
SYNOPSIS...Danzig
NEAR TERM...Danzig
SHORT TERM...Danzig
LONG TERM...Taber
AVIATION...Taber
FIRE WEATHER...Danzig