960
FXUS61 KBTV 190715
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
315 AM EDT Thu Jun 19 2025

.SYNOPSIS...
Warm and humid conditions will continue across the region for the
next few days. A cold front moving through the region today will
bring increased chances of strong storms that could produce damaging
winds and downpours, potentially leading to localized flash
flooding. Unsettled conditions will linger into the weekend before
high pressure builds over the eastern U.S. bringing the potential
for dangerous heat next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 315 AM EDT Thursday...A few pop up showers are occurring across
the Champlain Valley this morning, but otherwise all remains quiet
with temperatures falling into the 60s and lower 70s. Cloud cover
due to thick moisture continues to raise questions as to how likely
severe weather will be today.

A deep, positively tilted, vertically stacked closed low pressure
will cross the Great Lakes region today, approaching our forecast
area from the west and providing necessary forcing for what is
expected to be an active weather day. Temperatures rising into the
upper 70s to near 90 will be favorable for notable atmospheric
instability this afternoon as Surface CAPE values are modeled about
1500-2500 J/kg and 6km bulk shear around 40-60 knots. Precipitable
water values are anticipated to max out around 2 inches, though
concern for flooding issues is limited as flow remains fast out of
the south to southwest. The WPC maintains the Marginal Risk (1 of 4)
for excessive rainfall. Most unstable CAPE values are being modeled
around 1000-2500 J/kg, focused across the Champlain Valley eastward.
All that being said, we are looking at the potential for organized
line segments and clusters of severe thunderstorms this afternoon
with damaging wind gusts the most likely impact from these storms,
though torrential rain and large hail are also possible. The best
timing for thunderstorms continues to look to be in the mid to late
afternoon, but a strong morning thunderstorm is not out of the
question. One limiting factor of severe weather is the potential for
increased cloud cover this morning limiting daytime heating that
would destabilize the atmosphere enough to get distinct storms. SPC
continues to maintain the Slight Risk (2 of 5) of severe weather
across our region for today.

Thunderstorms will come to an end this evening/tonight, leaving
behind some lingering showers. Winds will be increasing out of the
southwest and west with gusts up to 20-30 knots likely occurring in
the pre-dawn hours of Friday morning. Highest gusts appear to occur
along the eastern slopes of the Adirondacks due to some downsloping.
At this time, winds are looking to be below Wind Advisory criteria,
but we will continue to monitor the potential need for one. It looks
like a good chance we`ll need a Lake Wind Advisory for Lake
Champlain starting in the early morning and continuing throughout
the day Friday. Lows tonight will be cooler than previous nights
following a cold frontal passage, but still seasonably mild in the
50s to lower 60s as cloud cover remains to accompany scattered to
isolated showers much of the night. Shower activity is forecast to
decrease gradually tomorrow, lingering longest in the mountains and
Northeast Kingdom. Skies will gradually clear from the south,
revealing some sunshine, and highs are expected to struggle to reach
the 70s. Gusty west to northwesterly winds will continue Friday
morning, more widespread across the Adirondacks through most of
Vermont, gusts 25-30 knots. These winds are modeled to decrease in
the afternoon/evening.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 315 AM EDT Thursday...Friday night will feature a weak
shortwave passing to our south. Most precipitation will slide south
of the region as dry air remains anchored north. Saturday afternoon
should be gorgeous. Surface high pressure will be right overhead.
Dewpoints will be somewhat humid, but nothing too uncomfortable with
mid 50s to lower 60s. A south to southwest wind will develop over
the course of the day. Enjoy the day while you can, but be prepared
for showers and thunderstorms Saturday evening into the overnight
hours. An elevated mixed layer will be positioned just to our
southwest, but a strong shortwave riding along it with a 50-60 kt
LLJ will set the stage for some nocturnal convection moving
southeast across the St. Lawrence Valley into Vermont. However, the
presence of that strong jet is not unanimous amongst forecast
guidance. A scenario with a weaker jet would place less convection
over our area. However, it appears likely that elevated
thunderstorms capable of very heavy rain and perhaps even some hail
if things line up will move through Saturday night. Behind the
shortwave, a surge of hot, continental air will rush east helping
scour out precipitation. There is high confidence in Wasted CAPE as
a capping inversion will set up and rising heights will produce
subsidence across the region. Dry, but increasingly hot and humid
weather is expected on Sunday with mid 80s to near 90 during the
hottest time of day with plenty of sunshine.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
As of 315 AM EDT Thursday...Probabilistic guidance remains consistent
in depicting hot weather Monday and Tuesday. Confidence on dangerous
heat is relatively high given how far out we are still. Monday will
likely be the hottest day. We encourage making adjustments to plans
to avoid doing strenuous activity during the hottest time of day
early next week.

When even raw ensemble guidance depicts greater than 50% chances of
heat indices of 95 F, that is fairly impressive. It`s roughly 70%
for Monday, even. The mid-level heat will come courtesy of the
Rockies, and the surface humidity will come courtesy of detouring
tongue of moisture out of the Gulf. Ensemble means are consistently
depicting 850hPa temperatures around 21-22C, which usually
translates to lower to mid 90s over the forecast area. There will be
a strong elevated mixed layer overhead on Monday, but mid-level
moisture will be lacking, and a capping inversion will be in place.
During the afternoon, it appears that the inversion could weaken
slightly, and that could allow for some isolated convection. Despite
the presence of an elevated mixed layer, the continued height rises
and lack of any feature may prevent significant updrafts from taking
place against very dry air. It`s more likely that the abundant CAPE
will go unused again to offer little relief against the heat.

On Tuesday, a cold front will drop south midday. One potential
scenario is that the cold front descends early enough that hot
weather is quickly capped off by clouds and precipitation. The other
is that it could arrive relatively late, allowing for another hot
day. This one has lower confidence in terms of how intense heat
could be. The strength of thunderstorm activity will depend on how
much we can destabilize ahead of the front. Although the elevated
mixed layer will not be as strong, we could still have fairly
favorable lapse rates to produce about 2000 J/kg of CAPE. At this
time, forecast soundings depict decreasing shear throughout the day,
though. Seasonable weather will return behind the front.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Through 06Z Friday...Mostly VFR conditions across the forecast
area early this morning except at RUT where low level moisture
has begun to approach from the south and southeast, leaving
ceilings there at about 2000-2500 feet above ground level. This
moisture is expected to continue its northward progression into
other sites throughout the early morning, producing MVFR or
lower cigs at the rest of the sites by about 08Z-15Z. Some sites
could even have ceilings dip as low as 500-1000 feet. This is
most likely at MPV from 10Z-13Z, but could occur briefly across
the rest of Vermont. Winds will be southerly to southeasterly
during this time frame, light overnight but increasing as we
head into the daylight hours Thursday, which is also what could
help mix out some of the lower ceilings.

We`ll see a return of VFR conditions by about 15Z except at
MSS, which could lag behind the others to about 19Z. A broken
line of showers and thunderstorms is expected between 18z and
23z on Thursday. The stronger storms will be capable of
localized strong and gusty outflow winds up to 40 mph, brief
heavy rainfall, and frequent lighting. Have continued to utilize
PROB30 groups for this potential with VFR and MVFR flight
categories, but a brief 15 to 20 minute window of IFR vis or
cigs are possible if a terminal gets a direct hit by a stronger
storm in the afternoon. Outside of thunderstorms, southwesterly
winds will gust 15-25 knots throughout the afternoon but should
lower again in the evening.


Outlook...

Friday: Mainly VFR, with local MVFR possible. Windy with gusts to
30 kt. Slight chance SHRA.
Friday Night: VFR. Slight chance SHRA.
Saturday: VFR. Slight chance SHRA, Slight chance TSRA.
Saturday Night: VFR. Likely SHRA, Slight chance TSRA.
Sunday: VFR. Slight chance SHRA, Slight chance TSRA.
Sunday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Monday: Mainly VFR, with areas MVFR possible. NO SIG WX.

&&

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

&&

$$
SYNOPSIS...Storm
NEAR TERM...Storm
SHORT TERM...Haynes
LONG TERM...Haynes
AVIATION...Storm