-- Discussion containing changed information from previous version are highlighted. --
767
FXUS61 KBTV 130925
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
525 AM EDT Sun Jul 13 2025

.SYNOPSIS...
A couple of rounds of showers and thunderstorms are on tap for today
and Monday as a slow-moving frontal boundary drifts across southern
Canada and into the Northeast United States. Heavy rainfall will be
possible with any thunderstorms, and localized flooding cannot be
ruled out. Drier weather resumes by Tuesday, but it will still be
hot and humid for the rest of the week.

&&

.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --
As of 519 AM EDT Sunday...Have issued an update this morning to
increase PoPs across central VT, where a batch of showers has
developed. This precipitation should gradually shift eastward
through the next few hours. Although somewhat isolated in
nature, this shower activity has produced around a quarter of an
inch, or even more, in just the few minutes time that it took to
pass over some locations. This speaks to how rainfall rates
could play out today and tomorrow. Note that WPC`s updated Day 1
ERO has upgraded much of northern NY to a Slight Risk, which
seems reasonable, though the highest risk should remain just to
the south of our CWA border today.

Previous forecast...The main focus for the near term will be a
slow moving frontal boundary which will bring a couple of rounds
of showers and thunderstorms to the region. Ample moisture will
pool along and ahead of the front, with PWATs approaching 2
inches, which is 2 to 3 standard deviations more than normal.
Given this, the biggest concern will be torrential rainfall with
localized flooding; note that we are in a Marginal Risk in
WPC`s Excessive Rainfall Outlook both Sunday and Monday, which
is indicative of a 5% risk of exceeding flash flood guidance.
Read on for details.

The front currently lies well to our west early this morning,
stretching from its parent low near Hudson Bay south/southwestward
through the Great Lakes and into the Midwest. This boundary will
gradually drift eastward through the day, eventually approaching the
St Lawrence Valley by this evening. In the meantime, heat and
humidity will build, and expect we`ll see SB CAPE values of 1000+
J/kg by this afternoon. This may be enough to allow a few
showers/storms to bubble up over the higher terrain or perhaps along
lake breeze boundaries through early afternoon, until better forcing
arrives with the approaching front later in the day. The bulk of the
activity will be from the Champlain Valley westward as eastern VT
looks to stay more capped with an inversion around 850mb. Scattered
to numerous showers/thunderstorms will cross northern NY into the
northern Champlain Valley through the evening, waning in coverage
and intensity as we lose daytime heating. Flow parallel to the
incoming front will allow for training of storms, and warm cloud
depths of 10 kft or more will enhance efficient rainfall processes.
Brief rainfall rates of 1 in/hr will be be possible, and we`ll have
to watch for training closely to see if cumulative amounts
approach/exceed FFG. Note that 6-hr FFG is 2+ inches; indeed, 3-hr
FFG is as well, except in those areas that received flooding
rainfall a couple of days ago (especially the NEK - more on that
below), and probabilities of 2+ in in 6 hours are 10% or less.
Still, isolated instances of flooding will be possible. Some of the
stronger storms may be capable of producing gusty winds as well,
perhaps approaching severe levels. Much of the area from the
northern Champlain Valley westward is included in a Marginal Risk
from SPC. It`ll be another hot and humid day, though increased cloud
cover should keep us a little cooler than yesterday. Highs will
generally be in the 80s with some spots in the wider valleys
approaching 90F.

After a muggy night tonight, Monday will be a near repeat of today;
the main difference will be that showers and thunderstorms will have
shifted further south and east along with the frontal boundary. The
focus will mainly be over VT, particularly northern and central
areas. As with today, all the same ingredients will result in
efficient rain makers, with rainfall rates of 1 in/hr at times. Note
that probabilities of greater than 1 in/hr have a bit more coverage
than today, with even a small area of 10% chance of more than 3
inches in 3 hours over portions of the Northeast Kingdom. Obviously
this area is of greater concern given the recent flooding; 3-hr FFG
is generally 1.5 to 2.5 inches in those locations. Please watch for
forecast updates as hopefully trends will become more clear with
subsequent forecast packages. Please remain weather aware over the
next couple of days.
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&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
As of 236 AM EDT Sunday...The front should finally make its exit to
our southeast Monday night, bringing showers and thunderstorms to an
end by midnight. A drier airmass will follow in its wake as ridging
briefly builds over the region. The result will be lots of sunshine
on Tuesday. We`ll also see a return to warmer temperatures Tuesday
as highs are expected to climb back into the mid 80s to low 90s.
Dewpoints will be in the 60s, so it`ll feel muggy, but we should
stay just below heat advisory levels.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 236 AM EDT Sunday...Eastern CONUS Heat ridge will nose across
CWA Tuesday night- Wednesday peaking wednesday with 925mb temps
reaching 24-26C at its peak. Dewpoints likely in the 60s to around
70F to put heat indices in the advisory range for most of our
wider valleys. During the transition Tuesday night...higher and
medium resolution models suggest decent shortwave riding along
the backside of the upper ridge with strong moisture pooling and
potential MCS development across Great Lakes riding along the
periphery of the ridge so at this time it looks like it will be
across Ontario-Quebec but will need to monitor.

It looks like the the earlier timing difference from the GFS the
last few days has come around as expected to the ECMWF/Canadian
solutions as northern stream shortwave lifts more NE thus front
slows in parallel SW upper flow. Therefore...warmer than
yesterday`s runs but cooler than Wednesday`s forecast highs and
rich moisture sending dewpoints into the lower 70s bringing heat
indices just under Wednesday`s reading but with a very warm
Wednesday night...can see needing an advisory as well,
especially CVly into VT.

 The front in parallel WSW flow will slowly move into and through
CWA Thu aftn through early Friday morning with rich PWATS of 1.75-2
inches, thus potential for heavy rain producers so we`ll need to
monitor closely.

By 12z Friday...front is likely across eastern New England with
surface high across the Great Lakes. Upper flow is still WSW across
the northeast and Great Lakes so the front brings some dewpoint
relief but temperatures are still AOB seasonable levels for Friday
and the weekend.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
Through 06Z Monday... VFR conditions will prevail for most sites
early this morning but ceilings are likely to drop aft 08z at SLK
and EFK will likely see them fall to MVFR. Ceilings at MPV may
go IFR for a couple hours as well. Ceilings will rise tomorrow
morning and they should mostly be VFR for the rest of the day.

There will be isolated showers around the Champlain Vly ard 12z,
otherwise dry until Scattered showers and thunderstorms develop
aft 18-20z timeframe. Brief MVFR or IFR visibilities will occur
in the heaviest storms. Winds will increase from the SSW with
gusts between 10 and 20 KTs are generally expected.

Aft 00z...winds will subside with lower ceilings developing and
possible fog where it rained earlier and continuing Sunday
night.

Outlook...

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

&&

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

&&

$$
SYNOPSIS...Hastings
NEAR TERM...Hastings
SHORT TERM...Hastings
LONG TERM...SLW
AVIATION...SLW