351
FXUS61 KBTV 210655
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
255 AM EDT Tue Jul 21 2026
.WHAT HAS CHANGED...
As of 249 AM EDT Tuesday...
No significant changes.
&&
.KEY MESSAGES...
As of 249 AM EDT Tuesday...
1. Multiple rounds of showers and storms today and tomorrow.
2. Blue sky conditions to end the week with cool and crisp air.
3. Quiet and hot weather is expected this weekend before
another storm system brings showers and thunderstorms to the region
early next week.
&&
.DISCUSSION...
As of 249 AM EDT Tuesday...
KEY MESSAGE 1: An occluding low will track well to the north today into
Wednesday, bringing several rounds of showers. A few showers will
move through this morning, but more widespread showers and
thunderstorms will move through in the afternoon and evening. They
will mostly dissipate and move out tonight, before another round of
showers and thunderstorms develops on Wednesday, though mostly for
Vermont. Right now, the severe threat is relatively low. There does
not look to be a well-defined boundary; instead several rounds of
showers with plenty of clouds will move through. There is very
little time for solar heating and instability to form, and the
airmass will be relatively cool to start with. With the low tracking
well to the north, the best synoptic forcing will be well to the
north, though there will be adequate wind shear. Overall, the region
is in an SPC marginal risk which seems representative. While an
isolated strong to severe storm is possible, that currently looks to
be the extent of it, though the amount of heating will still be
watched as more sun than expected could increase storm coverage a
little. The system does not look to provide much of a flooding
threat either. HREF probabilities of receiving more than an inch of
rain are generally between 10-40 percent. While there will be areas
of convective enhancement, the storms will be quick-moving and there
will be gaps between the showers. PWATs should rise into the 1.5-
1.75 inch range but with the expected setup, that should not pose
too much of a problem. While limited wildfire smoke may return
today, its concentration will be significantly less than on Saturday
and it will likely not have much of an effect on the convection.
KEY MESSAGE 2: A seasonably cool air mass, with minimal high altitude
smoke, should make for outstanding weather for outdoor activities on
Thursday and Friday as an upper level trough pushes to our
northeast. Westerly flow in the morning will probably support some
rough conditions on Lake Champlain that should improve during the
day as anomalous low level temperatures moderate along with
decreasing wind speeds. Winds decrease significantly for Friday.
Expect high temperatures not too far off of seasonable norms due to
abundant sunshine, currently projected to range through the 70s and
into the lower 80s. Lows at night will be in the 40s and 50s.
KEY MESSAGE 3: High pressure will dominate this weekend, resulting in
dry weather Friday night into Sunday. This is also allow for above
seasonable temperatures with highs in the 80s and lows in the 50s to
mid 60s as southwesterly flow aloft increases, advecting in warmer
air ahead of our next system. This next system is expected to swing
through early next week featuring a trough and cold front. This far
out, models show significant differences from each other as well as
from run to run, but most likely period of showers and thunderstorms
would be Monday. This should also knock temperatures back down
towards normal in the 70s to mid 80 and lows in the upper 40s to
lower 60s.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...VFR conditions will likely prevail at all
sites early this morning with some light south-southwesterly flow
limiting fog potential. Still, fog is not out of the question,
particularly at SLK where their dew point depression is suspiciously
low. Overall low confidence in anything occurring and how long it
may last. A warm front may produce some light, isolated showers this
morning, but most impactful showers and storms are expected to wait
until this afternoon and evening. The first wave will move through
southern Vermont around 15Z-16Z Tuesday, just showers and
potentially some MVFR ceilings, then another round of showers/lower
ceilings plus thunderstorms is anticipated at northern New York
sites beginning 18Z-20Z, moving east to Vermont sites by 20Z-22Z.
Strong wind gusts are possible with a few storms, especially in
southern St. Lawrence County. Outside of storms, we expect wind
gusts as high as 15-35 knots out of the south and southeast from 12Z-
18Z Tuesday onwards. A strong low level jet, fluctuating wind
direction from southerly to southwesterly, will likely make for some
periods of LLWS at all TAFs throughout the day Tuesday.
Outlook...
Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
&&
.MARINE...
A Lake Wind Advisory is expected to be in effect through
tonight. Southerly winds will quickly increase in the latter
portion of the night and by morning, sustained winds are
expected to be in the 20-30 KT range. These winds stay elevated
for the rest of the day and the evening. Winds will eventually
become westerly and decrease for late tonight and tomorrow,
dropping into the 10-20 KT range. Multiple rounds of showers and
thunderstorms are expected today, with stronger and erratic
winds possible in any of those. The highest coverage of showers
and storms will be in the afternoon and evening. Waves will
quickly build into the 2-4 FT range for today and this evening,
before eventually dropping into the 1-2 FT range late in the
night.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Myskowski
DISCUSSION...Myskowski/Storm
AVIATION...Storm
MARINE...NWS BTV
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