312
FXUS61 KBTV 021842
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
242 PM EDT Thu Jul 2 2026
.WHAT HAS CHANGED...
As of 240 PM EDT Thursday...
Some storms this afternoon/evening could be strong, especially near
the northern St. Lawrence Valley, and potentially near the Northeast
Kingdom. Have added the potential for gusty winds, localized heavy
rain, and frequent lightning to the weather through this
afternoon/evening.
&&
.KEY MESSAGES...
As of 240 PM EDT Thursday...
1. Our heat wave will continue through tomorrow across much of
the Northeast with unusually hot and humid conditions causing a
sharp increase in the risk for heat related illnesses.
2. The chances for thunderstorms and showers will continue into
this weekend with potential for a few strong to severe storms.
3. Warm weather will linger into next week, along with daily
chances of showers and thunderstorms.
&&
.DISCUSSION...
As of 240 PM EDT Thursday...
KEY MESSAGE 1: Dangerous heat will continue to impact Vermont and
northern New York today through Friday. Widespread temperatures in
the upper 80s to mid 90s have already been observed with heat
indices in the Champlain Valley already near 100F. The high heat
index values will be present through tomorrow afternoon.
Temperatures are currently in the upper 80s to low 90s. Today will
be the hottest of the week as the ridge axis crests over the region.
Contrary to yesterday however, dewpoints are not quite as high as
yesterday as some drier air aloft and better mixing has lowered the
low level moisture slightly. Regardless, dangerous heat index values
exceeding 100F in places are still expected, with tonight remaining
hot and muggy, limiting any relief from the hot and humid daytime
hours. We`ll see a bit of a respite from the humidity tomorrow and
Saturday, but it will still be very warm and muggy. North wind
advection will begin to slowly draw in some drier air tomorrow
lowering dewpoints back into the upper 50s to mid 60s by Saturday.
Subsequently, temperatures tomorrow will be a degree or two cooler
than today, and on the 4th, around the low to mid 80s, with some
locations in the upper 80s in the northern Champlain Valley and
lower Connecticut Upper Valley. Heat Index values for holiday
activities will be around the mid to upper 80s on Saturday. Sunday
will be the pick of the weekend with temperatures only i the upper
70s to low to mid 80s, and afternoon dewpoints in the low to mid 50s.
Heat related impacts will increase through tomorrow due to the
cumulative effects from the prolonged heat wave. Please make sure to
take proper heat safety precautions, including limiting your time
outdoors, drinking plenty of water, and seeking indoor shelter with
air conditioning. Check on your relatives and neighbors, especially
if they are elderly. And don`t forget about your pets; bring them
indoors or provide them with ample shade and fresh cool water.
KEY MESSAGE 2: Heat and humidity will combine to create impressive SB
CAPE values today between 2500-3500 J/kg today. Shear will be
slightly better today, up to 30-40 kts depending on the model, which
may lead to some better organization with any storms that develop
today. Satellite depicts an agitated cumulus field north of Lake
Ontario along a lake breeze, in addition to another area of agitated
cumulus north of Ottawa. Unlike yesterday, there are no pre-existing
thunderstorms upstream, and most activity today may be strictly
diurnally driven. Furthermore, shortwave upstream are not quite as
deep as yesterday as well, which may limit the overall coverage of
any showers. Given some persistence forecasting from yesterday, a
similar setup as yesterday is possible. Expectations are for some
clustering of storms to develop in eastern Ontario and southwestern
Quebec this afternoon, generally between 4-6 PM. These storms as
they become more organized will slide into the northern St. Lawrence
Valley, with potentially some stronger storms with gusty winds,
localized heavy rainfall, and frequent lightning. CAMs depict a
linear feature moving southeast from Massena into the northern
Adirondacks and becoming more broken and weakening southward between
6-8PM. Additionally, a weak shortwave Otherwise today, models show
some shower activity trailing the initial convection across northern
New York, making it into northern Vermont and the Northeast Kingdom.
These showers have a lower confidence of developing. With our mid
level flow generally easterly, anvils from Ontario may help
stabilize convection downstream into northern Vermont. Furthermore,
soundings still show an apparent EML remaining as a capping
mechanism to more robust storms. Still, there is a secondary
potential for some isolated to scattered showers and thunderstorms
across northern Vermont, mainly between 8-11 PM, given the
increasing instability across the region. Outside of the two
potential thunderstorm areas, any showers today will be heavily tied
to the higher terrain with no forcing mechanism present. Strong to
severe thunderstorms can`t be ruled out given the large CAPE values,
thought coverage will be less widespread than yesterday given not as
strong shortwaves. Still the SPC continues to encompass our entire
forecast area in a Marginal Risk (level 1 out of 5) for Today. Model
guidance during this Ring of Fire setup has been lackluster at best.
Convection across Wisconsin will likely persist towards eastern
Ontario close to sunset, based on persistence and upper flow
patterns, which may become our focal point for any activity across
Vermont later this evening. Any storms that pop up today would at
the least produce heavy rainfall, though widespread flooding is not
anticipated.
Additional storm chances exist tomorrow, mainly tied to the peak
heating hours as the ridge slowly shifts south. Cells tomorrow will
have similar shear profiles as the jet creeps southward, which will
lead to more clustering of storms. However, the axis of better
shower activity looks to shift more from Ogdensburg to Middlebury
and points south. This region is where the SPC has a Day 2 Marginal
Risk (level 1 out of 5) for the potential for some stronger storms.
Of note, is that the NAM3/HRRR denote a line of showers and
potential thunderstorms across the International Border, which
tracks to the southeast through the region between 6-10 PM, though
weakening as it moves through. Confidence in this feature is low at
the moment. A backdoor cold front will pass through the region
Friday night into Saturday night which will dramatically lower
dewpoints from the upper 60s to the upper 50s by Saturday. Some
shower activity with perhaps a rumble of thunder will be possible,
mainly in the southern regions, due to the presence of a forcing
mechanism. Shower activity will begin to taper off towards Saturday
afternoon/evening. Sunday looks to be the pick of the weekend with a
dry day expected.
KEY MESSAGE 3: Heading into next week, warm weather will linger,
although temperatures and heat indices will not be as warm as
currently. At this time, high temperatures are most likely to range
in the 80s and lower 90s with chances for showers and thunderstorms
each afternoon through midweek. Overnight lows remain on the warmer
side, generally in the 60s, which may lead to accumulating heat
impacts. The first part of the week won`t be too hot though.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Through 18Z Friday...VFR conditions are expected to prevail
through most of the forecast period. Additional chances for
showers and thunderstorms will be possible this evening, with
little confidence in areal coverage and intensity. Winds south
to southwesterly today, trending light and variable overnight.
There could be some fog formation overnight, but uncertainty
with cloud cover and shower development means that confidence is
low where we may have fog so I left it out.
Outlook...
Friday Night: VFR. Chance SHRA, Slight chance TSRA.
Independence Day: VFR. Chance SHRA, Slight chance TSRA.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. Chance SHRA.
Monday: VFR. Chance SHRA, Slight chance TSRA.
Monday Night: Mainly VFR, with local MVFR possible. Slight chance
SHRA, Slight chance TSRA.
Tuesday: Mainly VFR, with local MVFR possible. NO SIG WX.
&&
.CLIMATE...
Extreme heat and humidity will affect the region for the latter
half of the week, which could lead to some daily records. Below
are the current daily high and low temperature records in
jeopardy at our area climate sites.
Record High Temperatures:
July 2:
KBTV: 97/2018
KMPV: 90/2018
KMSS: 94/2018
July 3:
KMPV: 91/2002
Record High Minimum Temperatures:
July 3:
KBTV: 76/1911
KPBG: 73/2002
July 4:
KPBG: 71/1973
KSLK: 67/1952
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Heat Advisory until 7 PM EDT Friday for VTZ003-004-006>008-010-
016>020.
Extreme Heat Warning until 7 PM EDT Friday for VTZ001-002-005-
009-011-021.
NY...Heat Advisory until 7 PM EDT Friday for NYZ026-027-029>031-034-
087.
Extreme Heat Warning until 7 PM EDT Friday for NYZ028-035.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Danzig/Neiles
AVIATION...Neiles
CLIMATE...Danzig/NWS BTV
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