677
FXUS61 KBTV 122335
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
735 PM EDT Sat Sep 12 2026

.WHAT HAS CHANGED...
As of 215 PM EDT Saturday...

No significant changes to the forecast.

&&

.KEY MESSAGES...
As of 215 PM EDT Saturday...

1. Strengthening gusty south winds today and some showers
tonight.

2. Additional rounds of showers and some embedded thunderstorms
Sunday and Sunday night.

3. After cool conditions with potential for frost in outlying
areas Monday night, the progressive pattern will continue to support
periods of rain through the end of the week.

&&

.DISCUSSION...
As of 215 PM EDT Saturday...

KEY MESSAGE 1: After a beautiful first half of the weekend, tonight
will mark the transition to a more unsettled weather pattern with
strengthening gusty southerly winds and multiple rounds of showers
and some embedded thunderstorms expected through Sunday night/Monday
morning.

As surface high pressure shifts east of our area tonight,
strengthening southerly return flow will transport the higher PW air
mass (currently over the Mid-Atlantic states) northward into our
forecast area.  Precipitable water values will increase from around
0.6 inch today to 1.50-1.75 inches tonight. Gusty southerly winds
will continue to increase through the day today, especially
channeled up the Champlain Valley. With relatively warmer Lake
Champlain temperatures, forecast soundings are indicating enough
mixing is maintained below a low-level temperature inversion to
support Lake Champlain winds of 25 to 30+ knots overnight
tonight. A Lake Wind Advisory is in effect for Lake Champlain,
with winds expected to increase this evening and peak overnight
between midnight and sunrise. Outside of the Lake, expect gusty
winds 15 to 25 mph over the Champlain Valley, and 10 to 20 mph
elsewhere. Higher peaks will see gusts 45+ mph tonight.

A southern stream upper-level shortwave moving through overnight
will prompt the development of some showers tonight, with an
embedded thunderstorm or two possible due to some elevated
instability.  Up to 500 J/kg MUCAPE is progged overnight, highest
over our western counties in northern NY where the better chances
for a rumble of thunder exist. Outside of low thunderstorm
potential over northern NY, best chances for showers tonight
will be across southern Vermont, with lower probabilities
further north towards the International Border.

KEY MESSAGE 2:  During the day on Sunday, some rain showers will linger
over eastern and southern Vermont during the morning hours as the
system mentioned in Key Message 1 gradually exits to our east.
Meanwhile, most areas will then see a break in precipitation during
the day before the next system moves in from the west.  This next
system will be supported by strong dynamics as a potent shortwave
and associated cold front move into the region.

At this time, it continues to appear that the ingredients will not
line up ideally to support the development of widespread storms
later Sunday, though changes in the timing of the system and degree
of destabilization could increase the thunderstorm potential.
Current forecast has the break in rain during the day Sunday
that will allow between 500 and 1000 J/kg SBCAPE to develop
during the afternoon. However, the better forcing and dynamics
do not arrive until the early overnight hours, after the peak of
diurnal instability. Therefore, the most likely scenario is
some scattered showers with a few embedded thunderstorms during
the afternoon, with higher confidence in a brief round of a
wetting rain overnight for most areas as the stronger forcing
moves in. Additional thunderstorms cannot be ruled out
overnight, but instability will be limited and primarily
elevated. This will limit the severe threat, though any
thunderstorms that do develop Sunday or Sunday night could
produce gusty winds and cloud-to-ground lightning, especially
given the stronger background flow already in place. The Storm
Prediction Center maintains a Marginal Risk of severe weather
for much of our area on the latest Day 2 Convective Outlook.

Conditions will trend drier Monday as high pressure builds in.

KEY MESSAGE 3: High pressure crests Monday night with ideal raditional
cooling likely. Temperatures in the Adirondacks and northeastern
Vermont are favored to cool into the mid/upper 30s supporting frost
potential. Otherwise, 500 mb flow in the mid-high latitudes are
favored to be mainly zonal with Arctic air trapped well north of the
region keeping conditions near seasonal levels. Fast-moving troughs
will be moving through this flow with model trends maintaining a
weaker wave passing Tuesday night into Wednesday. Latest trends
continue to point to another wave Thursday into Friday with models
more consolidated resulting in higher probability of measurable
rainfall in this time period. Some model guidance keep the surface
boundary in the vicinity of Vermont/northern New York into the
weekend with WPC hanging onto 20-40% chances of showers before
another wave likely moves through sometime over next weekend. The
main take away here is that there periods of showers with
temperatures near seasonal levels during the day and above average
overnight due to pervasive cloud cover.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...VFR conditions for the first 6-12 hours of
the TAF period, but conditions lower to MVFR with local IFR as
showers spread from west to east overnight. Best chances for IFR
ceilings will be at SLK, and perhaps MPV and EFK as well.
Visibility to remain 4-6SM in showers, which will come to an end
10z-15z. Ceilings will lift thereafter, with all terminals to
return to VFR by 21z. South winds will remain breezy this
evening and overnight, especially in the Champlain Valley where
gusts to around 25 kt are expected. LLWS will develop outside
the immediate Champlain Valley overnight with showers spreading
after 06Z.

Outlook...

Sunday Night: VFR. Chance SHRA.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. Chance SHRA.
Wednesday: Mainly VFR, with local MVFR possible. NO SIG WX.
Wednesday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Thursday: Mainly MVFR, with areas VFR possible. Chance SHRA.

&&

.MARINE...
As of 215 PM EDT Saturday...

A Lake Wind Advisory remains in effect this evening overnight tonight
for strengthening south winds. Winds gusting 15-20 knots this
afternoon will increase to 20-30+ knots late this evening into
tonight. Winds will peak during the overnight hours, then will
diminish through the day on Sunday. Waves at 1 to 3 feet this
afternoon will build to 2 to 5 feet overnight, then become 1 to
3 feet again through the day on Sunday.

&&

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

&&

$$

WHAT HAS CHANGED...Duell
DISCUSSION...Duell/Boyd
AVIATION...Hastings
MARINE...Duell