934
FXUS61 KBTV 270741
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
341 AM EDT Fri Jun 27 2025

.SYNOPSIS...
Low clouds and patchy fog across Vermont this morning will give
away to increasing clouds by this afternoon with a few showers
possible over northern New York. Additional showers with a few
rumbles of thunder are possible overnight as a warm front lifts
across our region. For Saturday scattered to numerous showers
and thunderstorms are expected with some thunderstorms capable
of producing localized very heavy rainfall. Drier and warmer
weather returns for Sunday and Monday.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 307 AM EDT Friday...Latest trends have been for warm front
to lift north of our cwa on Saturday, placing our region in the
warm sector and shifting the heaviest qpf axis a little further
north. WPC has lowered the excessive rainfall risk from SLGHT to
MRGL acrs our fa for late tonight into Sat, given recent trends.
However, still plenty of ingredients available for localized
heavy rainfall on Saturday associated with a cold frnt, which
could produce a localized/isolated flash flood threat acrs our
mountainous trrn.

Sfc analysis places 1026mb high pres south of Hudson Bay, which
has helped to drive drier/cooler air south with some patchy fog
acrs VT early this morning. Meanwhile, low pres is located over
n-central Iowa with warm frnt extending eastward acrs the Ohio
Valley and trailing cold frnt over the central MS Valley. As sfc
low pres tracks acrs the western Great Lakes into central Canada
a warm frnt and associated moisture wl lift acrs our region late
today into tonight. The timing of moisture/lift has been
delayed, which should result in a mostly rain free Friday.
Also, boundary is now expected to lift north of our cwa by late Sat
morning, which places best convergence and gradient for
heaviest precip north of our cwa, as we become established in
the warm sector.

Deep moisture with pw values surging btwn 1.50 to 1.75"
develops acrs northern NY by late today and spreads into VT
overnight. This waa lift and moisture advection, combined with
an axis of elevated instability wl produce a band of showers
with embedded thunder btwn 21z and 06z this evening. Additional
s/w energy is expected to travel near the International Border
btwn 09z-15z Saturday, producing additional showers/storms over
extreme northern NY/VT on Sat morning. Given low tracking well
to our north and west, feel warm frnt and ridging aloft develop
to push initial band of moisture north of our cwa by 15z
Saturday.

However, as cold frnt and s/w energy associated with mid/upper
lvl trof approach additional showers/storms are likely on Sat
aftn. Given pw values btwn 1.75 and 2.0, warm cloud depths of
11,500 to 12,000 feet and dynamics with approaching trof,
localized heavy downpours are likely within the stronger
convection. Difficult to pin point exact locations of stronger
convection, but given deep moisture profiles localized rainfall
rates of 1.0 to 2.0 inches per hour wl be possible, which could
cause some very isolated flash flooding, if this was to happen
acrs complex trrn. For this reason, WPC has continued with a
marginal threat risk for excessive rainfall. As cold frnt sweeps
acrs the fa, much drier air develops by 00z and threat for any
flooding quickly ends. Highs on Saturday are tricky with
clouds/precip in the morning, followed by some clearing with
warm sector. Have trended on the warmer side of the NBM with
highs mid 70s to lower 80s, but if more sun develops with
progged 925mb temps in the 16-19C range, highs could warm well
into the 80s. This would create more instability and combined
with favorable shear would increase the potential for a few
stronger to localized severe storms on Sat. Plenty to monitor
with upcoming system.



&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 307 AM EDT Friday...Building mid-level heights and surface high
pressure will build from west to east across the North Country
Saturday night which should allow for a quick and abrupt end of
rainfall around midnight Saturday night. This is quite a bit quicker
compared to previous guidance 24 hours ago but should help continue
to mitigate any flood risk as we head into the overnight hours on
Saturday. Sunday will be on the dry side as deep layer ridging build
overhead. Light winds, sunny skies, and warmer temperatures will be
in store on Sunday as we begin to see some modest warm air advection
across the region. Quiet weather will continue into the evening
hours with decent cooling expected Sunday night under clear skies.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 307 AM EDT Friday...Monday will be the warmest day of the week
with many places warming into the mid to upper 80s with some 90
degree temperatures possible in the Champlain, Lower Connecticut,
and St. Lawrence Valleys. Dewpoints will only be in the 60s on
Monday which won`t be as oppressive as the dewpoints seen in the
previous significant and record setting heart. Nonetheless, it`ll be
warm on the humid side so plan accordingly if you`ll be outdoors on
Monday. The deep layer ridging that will be responsible for this
warm up will slide eastward Monday night which will usher in the
return for rain chances across the region. There is some uncertainty
to how quickly rainfall will return to the region as the GFS has a
series of shortwaves moving in as early as the pre-dawn hours on
Tuesday while the global consensus keeps rain chances at bay until
Tuesday morning. The biggest question for Tuesday is if we will be
able to have a break in rainfall/cloud cover to destabilize in the
warm sector ahead of an approaching cold front. With the lack of any
high res guidance this far out, we have analyzed some ensemble data
with guidance suggesting 500-1500 J/kg of CAPE depending on how the
morning plays out. Model sounds overall look pretty unimpressive
with only modest mid-level lapse rates so we could see a few
stronger storms but it seems unlikely to see any severe storms based
on the data we are seeing at this time.

Following the cold front on Tuesday, we should see a return to
seasonal temperatures for the second half of the work week. We will
remain under broad cyclonic flow within an upper level trough
through Wednesday through at least Friday, if not longer, which will
allow for daily rain chances as we have some decent mid-level lapse
rates, shortwave energy, and decent heating each afternoon. No
significant weather is expected after Tuesday so it should be a
pretty nice second half of the week.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
Through 06Z Saturday...Mainly VFR conditions will prevail at our
7 taf sites for the next 12 to 24 hours. Confidence in fog
development with IFR or lower flight categories is <15% given
mid/upper level clouds advecting across our taf sites early this
morning. Best potential would be for a few hours at MPV between
06z and 10z. Otherwise, south/southeast winds increase late
morning into the early aftn with localized gusts up to 20 to 25
knots possible at BTV/RUT. As a warm front lifts across our
region late this aftn into the evening hours a period of rain
showers are possible, especially across our northern NY taf
sites. Timing and impacts are still a little uncertain, but
brief MVFR vis or cigs are possible in the heavier shower
activity.

Outlook...

Friday Night: Mainly VFR, with local MVFR possible. Definite
SHRA, Slight chance TSRA.
Saturday: Mainly MVFR, with local IFR possible. Definite SHRA,
Slight chance TSRA.
Saturday Night: Mainly MVFR, with local IFR possible. Chance
SHRA, Slight chance TSRA.
Sunday: Mainly MVFR, with local IFR possible. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. Slight chance SHRA, Slight chance TSRA.
Monday Night: VFR. Chance SHRA, Slight chance TSRA.
Tuesday: Mainly MVFR, with local IFR possible. Likely SHRA,
Slight chance TSRA.

&&

.HYDROLOGY...
The threat for excessive rainfall and the potential flash
flooding threat has decreased across much of the North Country
tonight into Saturday. Several rounds of showers and
thunderstorms are expected on Saturday with localized heavy
rainfall possible in the stronger storms. Very isolated flash
flooding is possible, especially if a mountain basin has several
direct hits from thunderstorms on Saturday. Any flood threat
quickly ends by sunset on Saturday evening.

&&

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

&&

$$
SYNOPSIS...Taber
NEAR TERM...Taber
SHORT TERM...Clay
LONG TERM...Clay
AVIATION...Taber
HYDROLOGY...NWS BTV