373
FXUS61 KBTV 121829
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
229 PM EDT Wed Aug 12 2026
.WHAT HAS CHANGED...
As of 228 PM EDT Wednesday...
No significant changes we made to the forecast.
&&
.KEY MESSAGES...
As of 228 PM EDT Wednesday...
1. Isolated to scattered showers and thunderstorms expected
this afternoon, and Thursday afternoon as a pair of shortwaves move
through the region. Conditions turn drier and quieter by Friday and
Saturday.
2. Showers return for late Sunday and the beginning of next
week.
&&
.DISCUSSION...
As of 228 PM EDT Wednesday...
KEY MESSAGE 1: Isolated to scattered showers and thunderstorms are
beginning to move through the area this afternoon as a shortwave
axis centered over western Ontario slowly pivots east. Upper level
northwesterly zonal flow is set up across New England on the
periphery of a stagnant ridge over the Plains and Intermountain
West. Marginal instability around 1000J/kg is analyzed by on
mesoanalysis providing the fuel for showers and storms today.
Additionally, effective bulk shear to around 35-40 knots may lead to
some locally gusty winds up to 30 MPH under any thunderstorms.
However, given the marginal instability, weaker mid level lapse
rates, and an apparent cap around 700mb based on satellite cloud
presentations will keep any severe threat low through this evening.
Best chances for any stronger storms will be across the St. Lawrence
Valley where the best CAPE gradient is. A few training storms will
be possible with storm motion paralleling the mean flow. However,
deep moisture will be lacking with PWs only to around an inch. Thus,
any risk of flooding will be slim. While a few isolated showers may
continue through the overnight hours, any thunderstorm activity is
expected to wane beyond sunset.
Another shortwave is expected to move through tomorrow, with better
aligned forcing for our region. Increasing diurnal instability
around 1000-1500J/kg focused around the International Border with
similar shear profiles will bring better chances for thunderstorms
to the region tomorrow afternoon, though a few showers may be
possible in the mid to late morning with little capping inversion
present. Instability will highest in northern Vermont, though
showers and thunderstorms anywhere across the northern portions of
the CWA will be possible tomorrow. PWs will slightly increase
tomorrow to near an inch and a quarter, with parallel motion and
training cells. However, again, deep warm cloud depths will be thin
with a low risk for any flooding concerns.
Troughing will slide east with surface high pressure building in by
Friday. More calm and quieter conditions are expected through
Saturday. Temperatures will be relatively seasonable in the mid to
upper 70s. A radiational cooling night is increasingly likely Friday
night with lows potentially dipping to the upper 40s to low to mid
50s. A few pocket low 40s may be possible in the decoupled protected
valleys of the Adirondacks and eastern Greens.
KEY MESSAGE 2: An area of low pressure enters the region for late
in the weekend and early next week, bringing another round of
showers to the region. The track of the low will determine the exact
impacts. Right now, a track slightly south is favored, bringing a
period of steady rain. However, some ensemble members bring the low
just far enough north to push the warm sector into at least southern
areas. This would cause some severe potential, so the threat will be
watched. GEFS/EPS/CMCE combined probabilities of receiving more than
an inch of rain are under 10 percent, and probabilities of a half
inch are from 10-30 percent. Overall, not much of a flood threat is
expected. Behind the system, temperatures should trend seasonably
cool with a couple additional chances of showers.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Thursday...Scattered showers and storms will move through
this afternoon and evening, bringing brief periods of heavy rain.
Thunder will occur in the heaviest showers, and there is probably
around a 30-40 percent chance that a given terminal sees lightning
in the vicinity. These showers should mostly end by late evening,
though a couple lingering isolated showers are possible overnight.
However, by this time, the thunder threat is over. These showers and
storms will cause brief visibility reductions, with a period of MVFR
or IFR visibility occurring during the storms. Patchy fog
development will occur later in the night. It is expected to reach
MPV and SLK, and there is a chance (~30 percent) that it forms at
EFK. Areas that see rainfall today will see locally higher
probabilities of fog formation. The fog should lift by 13Z and VFR
conditions are expected through the rest of the morning. Winds will
generally be under 10 KT, except during storms where erratic gusts
up to 30 KT are possible.
Outlook...
Thursday Night: VFR. Slight chance SHRA.
Friday: VFR. Slight chance SHRA.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. Chance SHRA.
Sunday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.
Monday: MVFR/IFR conditions possible. Slight chance SHRA, Slight
chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Myskowski/Danzig
AVIATION...Myskowski
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