857
FXUS61 KBTV 272320
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
720 PM EDT Sat Jun 27 2026

.WHAT HAS CHANGED...
As of 255 PM EDT Saturday...

No significant changes made with this forecast package.

&&

.KEY MESSAGES...
As of 255 PM EDT Saturday...

1. Pleasant weather conditions are expected through Monday with
comfortable humidity, seasonable temperatures and dry conditions,
before heat and humidity return by Tuesday, along with showers
chances.

2. Hot and humid conditions expected for mid to late next week,
with multiple rounds of showers and thunderstorms possible through
the holiday weekend.

&&

.DISCUSSION...
As of 255 PM EDT Saturday...

KEY MESSAGE 1: A narrow axis of mid lvl moisture, combined with some
sfc instability from lingering bl moisture and heating has produced
a few isolated showers over the Dacks. These showers wl dissipate
with the loss of sfc heating/instability by sunset. Thinking patchy
to areas of dense fog wl be likely again tonight, but probably not
as widespread as last night, given a day removed from rainfall and
slightly drier bl conditions. However, sfc dwpts in the 55-60F range
this aftn, feel temps drop quickly aft sunset with many climo
favored sites reaching cross-over values by 06z, supporting the
development of fog/br under mostly clear skies and light trrn driven
winds. Lows in the upper 40s SLK to near 60F BTV.

Sunday thru Tues a large scale pattern amplification occurs acrs
the conus with deep 3 to 5 std below normal hghts acrs the
western conus and building heat ridge over the MS/OH valleys.
This synoptic scale pattern supports building heat and humidity
acrs our cwa by Tuesday as ridge expands toward the Mid Atlantic
States. A warm frnt with increasing moisture advection wl
traverse our cwa on Tuesday with a band of showers and embedded
thunderstorms. Instability wl be building behind the best warm
frontal lift/moisture, so threat for strong/severe storms wl be
minimal on Tues. Instead of 12 to 18 hours of likely or higher
pops per NBM solution, given the timing differences, I cut 20 to
30% and kept pops in the chc range for now. As timing becomes
better with near term high res guidance we can fine tune the
pops to better match our thinking.

Progged 925mb temps are 17-20C on Sunday and Monday, but warm btwn
23-25C by Tuesday but with increasing clouds/showers possible. For
now I have highs upper 70s to mid 80s Sunday/Monday and warm temps
into the mid/upper 80s by Tues with bl dwpts warming into the mid
60s. Heat index values wl approach 90F by Tues in the SLV and CPV
with 80s in the mtns. In addition, overnight lows wl be warming from
the 50s into the 60s by Tues morning.

KEY MESSAGE 2: Summer officially arrives by mid next week with
temperatures continuing to warm through mid week into the holiday
weekend, peaking on Wednesday and Thursday. Ridging will crest over
the Ohio Valley and extend into the Northeast by mid week, though
some uncertainty remains on how extended the axis will be. Current
trends have placed Vermont and northern New York potential on the
eastern periphery of the ridge along a temperature gradient. This
gradient will play a large role for how our weather plays out
heading into the holiday weekend. Temperatures will peak towards the
upper 80s to low 90s, with the NBM denoting the possibility of
warmer temperatures. 925 and 850 mb temperatures in the ensemblistic
guidance still only show values in the low to mid 20Cs, which would
not bode temperatures above the mid 90s. Furthermore, guidance
continues to show that reaching the low to mid 90s may be difficult
as some ridge rollers along the periphery of the Ohio Valley ridge
may lead to some increased cloud cover and afternoon shower and
thunderstorm chances. With these patterns we tend to have a warm
bias initially leading to the event as predicting the timing and
position of these mesoscale features and convective debris clouds
are difficult for the models to resolve. Regardless however,
dewpoints will also increase towards the upper 60s to low 70s for
Wednesday/Thursday. As dewpoints will be high, so will overnight
lows, which will offer little relief with lows in the low to mid
70s. With the combination of the heat and humidity, heat index
values may be around 100F. Should these heat index values become
realized, the heat risk will be at or above major for Wednesday and
Thursday for the entire region. In addition to the heat, daily
chances for thunderstorms, some that may be strong, will be
possible. With the increased heat leading to increasing instability,
and high dewpoints, a recipe for strong thunderstorms is growing
more confident for Wednesday and Thursday. Dangerously hot and humid
conditions are expected nonetheless and anyone with outdoor plans
through Thursday should stay aware of future forecasts and include
both hot weather and thunderstorm safety precautions in your plans.

As we near the 4th of July and the holiday weekend, there may be
some respite from the heat. The ridge axis shifts a bit south on the
4th, though temperatures will still remain in the upper 80s to low
90s with dewpoints in the mid to upper 60s. Heat and humidity will
continue to slowly lower into the weekend with high temperatures
into the mid to upper 80s.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...Cumulus is beginning to dissipate as peak
heating has passed. Skies will be mostly clear overnight, and
fog is expected to develop overnight. Fog is not expected to be
quite as widespread being removed from precipitation about a day
and having lower crossover temperatures. Still KMPV and KSLK may
start falling below 1SM around 04-06z, and even less fog prone
airports may still have fog nearby or briefly note drops in
visibility, which are noted in TEMPOs. After 12z, fog should
quickly dissipate and a few fair weather cumulus generally at or
above 5000 ft agl are expected with northwest winds 4-9 knots.

Outlook...

Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. Chance SHRA, Chance TSRA.
Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Chance TSRA.
Wednesday: VFR. Slight chance SHRA, Slight chance TSRA.
Wednesday Night: VFR. Chance SHRA, Chance TSRA.
Thursday: VFR. Chance SHRA, Slight chance TSRA.

&&

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

&&

$$

WHAT HAS CHANGED...Taber
DISCUSSION...Taber/Danzig
AVIATION...Haynes