462
FXUS61 KBTV 102352
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
752 PM EDT Fri Jul 10 2026
.WHAT HAS CHANGED...
As of 227 PM EDT Friday...
No significant changes.
&&
.KEY MESSAGES...
As of 227 PM EDT Friday...
1. Seasonable and dry weather this weekend before temperatures
and humidity increase early next week.
2. A brief burst of heat will give way to a steadier period of
more seasonable weather following a risk of nocturnal severe
thunderstorms.
&&
.DISCUSSION...
As of 227 PM EDT Friday...
KEY MESSAGE 1: A cold front passed through this morning, causing a
cooler and significantly drier airmass to enter the region straight
down from Quebec. Dew points have been gradually falling during the
day and that trend will accelerate this afternoon as the core of the
drier air makes its way south, aided by diurnal mixing. By evening,
dew points should be in the 50s throughout the region, with some
upper 40s in the higher terrain and Northeast Kingdom. Canaan has
already has seen its dew point drop to 49! Highs in the upper 70s
and 80s will be in store for this weekend, with lows in the 50s away
from the immediate shore of Lake Champlain. The colder hollows
should see lows drop into the 40s. Increased heat and humidity will
enter the region to start next week, with highs rising into the 80s
and low 90s and dew points rising into the 60s. The first chance of
showers does not appear to be until Tuesday at the earliest.
KEY MESSAGE 2: Signals for a brief, "jailbreak" style extreme heat
event on Tuesday have only increased with the latest ensemble data.
Based on the full 00Z suite and much of the 12Z data today, there is
excellent multi-model support for either low level temperatures near
the 98-99 percentile, or slightly less extreme temperatures near the
95th percentile, by Tuesday afternoon. Therefore, there is high
certainty that anomalous warmth associated with the eastward
expansion of a prominent deep layer ridge, or heat dome, centered
over the Midwest makes its way into the area on Tuesday. As
previously noted, this heat will should not be particularly humid as
it will be displaced from the typical sources (eg. southern Pacific
or Gulf moisture). That being said, low level flow out of the
southwest should still advect in higher dew points with
uncomfortable heat lingering past sunset. The latest thinking is
that marginal Heat Advisory criteria will be reached; maximum heat
index values could be in the middle 90s in the Champlain Valley and
Lower Connecticut Valley with lower 90s in most other valley
locations. Also it appears higher dewpoints will be favored towards
the northwest such that the St. Lawrence Valley may be on the humid
side. Will note the current NBM temperatures peaking as high as the
upper 90s are running a little hot compared to the consensus, so
anticipate forecast temperatures and resulting heat index values to
trend closer to those mentioned. Since this is a single hot day,
heat-health impacts aren`t anticipated to be as significant as a
longer duration event but will be meaningful for vulnerable
populations.
Much cooler and dry air will return on Wednesday behind a strong
cold front. Said front will act as a trigger for thunderstorms late
Tuesday in southern Canada as moisture pools ahead of this boundary,
producing a highly unstable environment favorable for supercells or
even derecho-like linear storms given very high deep layer shear (60-
70 knots favored). Impacts for our area, with expected timing
centered around the overnight hours and long lead time with
formation of storms favored much to our north, are questionable (15%
risk of severe thunderstorms currently noted by the Storm Prediction
Center), but will be worth keeping an eye on as we get closer,
especially in northern and northeastern Vermont. Largely seasonably
and comfortable weather will follow, with perhaps a weaker cold
front coming through to reinforce cooler air by the end of the week.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Through 00Z Sunday...Dry weather is expected this weekend
following this evening`s cold front, which continues to cross
from north to south through northern New York and Vermont. As a
result, wind directions are mainly northerly to northwesterly
3-10 knots. We do anticipate winds to decrease into the evening
and overnight hours, becoming calm or light, generally 5 knots
or less as high pressure exerts its control over the region.
From the hours 05Z through 12Z Saturday, there is the potential
for some patchy mist or fog and ceilings below 1000 feet above
ground level. Highest confidence of this occurring is at MPV
from 09Z to 11Z, based on the fact that the area has received
nearly a half an inch of rainfall in the past 24 hours.
Climatologically, this 09Z-11Z time frame is the most favored,
but fog may develop before and/or linger later. Other
potentially foggy spots will be SLK and EFK, though confidence
at EFK has decreased as climatology indicates there is a lower
chance there, especially as drier air flows into the region from
the north. Climatology at SLK is in turn more favorable for fog,
but it has not received very much rain in the last 24 hours or
even the last few days. One thing SLK has going for it is the
potential for its temperature to drop dramatically tonight and
pass its crossover temperature. BTV may have some fog approach
the runway if the fog develops across the Winooski Valley and
flows towards this site, but again drier air may limit the
extent of this. Elsewhere, winds should remain elevated enough
to keep fog away, but it`s not completely out of the question
with high pressure nosing in. Friday, we`ll see winds pick up
again out of the north, 5-15 knots.
Outlook...
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. Chance TSRA, Slight chance SHRA.
Wednesday: VFR. Slight chance SHRA, Slight chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Myskowski
DISCUSSION...Kutikoff/Myskowski
AVIATION...Storm
|
