817
FXUS61 KBTV 131840
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
240 PM EDT Sun Sep 13 2026
.WHAT HAS CHANGED...
As of 325 AM EDT Sunday...
No significant changes made to the forecast.
&&
.KEY MESSAGES...
As of 325 AM EDT Sunday...
1. Several rounds of showers and embedded thunderstorms are
expected today into tonight, with a low probability (<15%) of a few
stronger storms possible.
2. Changeable weather conditions every couple of days as fast
progressive flow aloft prevails most of this upcoming week, but the
probability of significant or hazardous weather impacts is <5%.
&&
.DISCUSSION...
As of 325 AM EDT Sunday...
KEY MESSAGE 1: Crnt radar imagery shows a band of widespread light to
moderate rain impacting most of our cwa this morning associated with
deep moisture advection and channeled 700-500mb vorticity. This
moisture and energy should shift east of VT by 15z this morning with
some breaks in the overcast expected by early aftn. These breaks
should allow temps to warm into the mid 70s to lower 80s with dwpts
in the 60s, creating sfc based CAPE values in the 800-1200 J/kg.
However, sounding data does suggest a warm nose of 13-14C air near
800mb, which could act as a cap until better forcing and cooler air
aloft arrives late in the day/this evening. Also, subsidence/dry air
behind initial moisture surge this morning may limit areal coverage
of any convection this aftn. SPC continues to place most of our cwa
in a marginal risk for severe, but feel threat is very conditions
with limited areal coverage and intensity of storms anticipated due
to the combination of factors outlined above. However, if a
convective updraft can grow tall enough, given the developing
mid/upper lvl lvl wind fields, an isolated gusty thunderstorm would
be possible. The threat for stronger storms dissipates after sunset,
but additional showers are likely overnight associated with our sfc
cold frnt and potent 700-500mb s/w energy dropping southward. The
dynamics and ribbon of moisture wl produce a line of quick moving
showers from west to east acrs our cwa btwn 03z-09z Monday.
Moderate caa develops behind the boundary for Monday with lingering
clouds, especially in favorable upslope regions thru early aftn,
before drier air develops and skies become mostly sunny. Highs only
in the upper 50s to upper 60s with brisk northwest winds. Building
1028mb high pres and associated deep dry layer wl result in mostly
clear skies and light winds on Monday night, expect areas of fog
with some patchy frost likely in the dacks/nek by Tues morning. Lows
from the upper 20s to mid/upper 40s anticipated acrs the region.
KEY MESSAGE 2: The large scale synoptic pattern conts to indicate a
fast/zonal flow acrs the northern CONUS for most of this upcoming
week. This will provide our cwa with changeable weather conditions
every couple of days but the probability of significant or
widespread hazardous weather impacts is very low attm. Temps wl
trend at or slightly below normal for most of this upcoming week
with highest probability of showers late Weds into Thurs. Precip
setup looks very similar to our crnt scenario with 700-500mb
vorticity lobe angling acrs our cwa as sfc cold frnt is dropping
southward. This wl support expanding areal coverage of showers and
embedded heavier downpours late Weds into Thurs, especially with pw
values near 1.5". Similar to this mornings activity, highest
pops/qpf looks to be acrs central/southern areas, closer to the
deeper moisture/weak instability, but this could change as the week
progresses. Temps mostly in the upper 60s to mid 70s with lows mid
40s to mid 50s.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Through 18Z Monday...A mix of MVFR/VFR cigs will continue
through around 20Z until sun breaks through the cloud cover and
mixing increases; mixing has been slower than anticipated which
has kept MVFR conditions longer than anticipated for select
terminals. Main threat to aviation will be the potential for
some afternoon thunderstorms as a front moves through. This
front has been victim to the cooler temperatures keeping
thunderstorms exceedingly isolated, but that will change 18-23Z
as instability maximizes. Highest chances remain in the St
Lawrence Valley, but can`t rule out some thunder in the
Champlain Valley as the front tracks east. As the boundary
tracks east, some LLWS is likely at MPV/EFK 04-12Z. Flow turns
from southerly this afternoon and evening to northwesterly by
12-15Z Monday. Aviation challenge this morning will be cigs and
vis as light to moderate rain exits Vermont by 15z.
Outlook...
Monday Night: VFR. Patchy BR.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: VFR. Slight chance SHRA.
Wednesday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Thursday: MVFR/IFR conditions possible. Chance SHRA.
Thursday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Friday: VFR. Slight chance SHRA.
&&
.MARINE...
As of 325 AM EDT Sunday...
A Lake Wind Advisory continues today for gusty south to southwest
winds 15 to 30 knots with a few localized gusts up to 35 knots
possible this morning across the open waters. Waves generally 1 to 3
feet, but locally 3 to 5 feet possible. Winds slowly decrease this
afternoon to 15 to 20 knots before shifting to the northwest
overnight. Another Lake Wind Advisory maybe needed for late tonight
into Monday morning for breezy northwest winds 15 to 25 knots and
waves 1 to 3 feet.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Taber
DISCUSSION...Taber
AVIATION...Boyd/Taber
MARINE...Taber
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