South Burlington, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

031
FXUS61 KBTV 271107
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
707 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 646 AM EDT Friday...Minor update to tweak pops this
aftn/evening associated with warm front lifting from sw to ne
acrs our cwa. This results in rain showers arriving in northern
NY aft 18z and toward 22z for parts of the CPV/northern VT.
Also, continued fog for another hour or two acrs central/eastern
VT valleys, where MPV is crntly 1/4SM in FG. Rest of fcst in
good shape.

Previous discussion:
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 /12Z FRIDAY THROUGH TUESDAY/...
Through 12Z Saturday...Fog that developed at MPV will dissipate
by 13z this morning with VFR conditions prevailing at all taf
sites thru 00z this evening. As a warm front approaches light
rain showers with embedded heavier downpours will impact MSS
btwn 20-24z and spread into SLK/PBG/BTV and EFK btwn 22z and
04z. These showers should lift north of our terminals by
midnight, with developing south winds at 10 to 20 knots. Some
localized gusts up to 25 knots possible at RUT/BTV. Also, as low
level jet increases the potential for areas of wind shear and
turbulence increase overnight. CIGS will lower toward MVFR as
deeper moisture develops overnight acrs our terminals.

Outlook...

Saturday: Mainly VFR, with areas MVFR possible. Definite SHRA,
Slight chance TSRA.
Saturday Night: Mainly VFR, with local IFR possible. Chance SHRA,
Slight chance TSRA.
Sunday: Mainly MVFR, with areas VFR 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