-- Discussion containing changed information from previous version are highlighted. --
006
FXUS61 KBTV 282341
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
741 PM EDT Sat Jun 28 2025

.SYNOPSIS...
A cold front will swing through the region this afternoon and
evening which will bring an end to our rain chances with
increasing sunshine and seasonal weather expected on Sunday. A
significant warm up is expected Monday as highs climb into the
mid 80s to lower 90s but these temperatures will be short-lived
as another cold front moves through the region on Tuesday.
Several round of rain and thunderstorms will be possible late
Monday and again on Tuesday, a few potentially producing heavy
rainfall. Conditions will then trend cooler for the latter half
of the week.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 651 PM EDT Saturday...Not a lot of changes to the forecast
in this update. Temperatures are running a few degrees warmer
across northern New York where more clearing has developed this
afternoon. On the contrary, across eastern Vermont, temperatures
are a few degrees cooler where more cloud cover is present, but
is gradually eroding to the east. Shower and thunderstorm
chances have lowered with more stable air across northern Vermont,
and a weaker cumulus field in northern New York per satellite
observations. A few weak pulse showers are developing along a
convergence line in northern St. Lawrence County, but that is
all that is currently across the North County. These showers
will go up and quickly subside as they near the international
border. A secondary convergence line just north of the Mohawk
Valley in New York is spurring some showers and thunderstorms.
These should weaken as they approach Vermont, but an isolated
rumble of thunder is possible tonight across southern Vermont.

Previous Discussion...It`s a classic set up, with high contrast
air masses over the forecast area. East of the Greens remains socked
in with maritime air. The Caledonia Airport remains at 58 degrees.
Meanwhile, the warm front has lifted north on the west side of the
Greens, and the Patrick Leahy Burlington International Airport has
risen to 80. Massena, NY has similarly warmed to 82 with dewpoints
rising to 70 as moisture continues to increase. However, this
moisture is almost entirely confined to the low-levels. Water vapor
imagery shows a significant dry layer over northern New York and
beginning to impinge across northern Vermont. Beneath it, convection
has remained shallow and has been unable to develop. Farther south,
sufficient moisture and better instability are allowing
thunderstorms just east of Lake Ontario and in Pennsylvania. This
airmass will gradually lift east- northeast towards Vermont, but flow
will continue to back across Vermont to reinforce the maritime air
mass. This will erode instability fairly quickly as the line
approaches. There will only be a narrow tongue of instability nosing
up the Taconics into the far southern Champlain Valley. Any
thunderstorm that can hold its own beneath a moderately favorable
upper level pattern may still produce a strong storm and perhaps a
severe storm in far southern Vermont. Everything up north will
remain strictly garden variety.

Tonight, the front will cross east in piecemeal fashion. There`s a
dewpoint boundary and wind shift that occurs near midnight, and a
few showers could develop along the international border and amble
into north-central Vermont and the NEK later overnight. Otherwise,
the front washed out. So we should remain somewhat warm in the mid
50s to mid 60s. Some fog will be possible in eastern Vermont
wherever the front fails to cross.

Sunday will be fantastic. Mid 70s to mid 80s, relatively comfortable
air, and a steady breeze with ample Sun. No notes here!

Sunday night, high pressure will start sliding east, but it
looks like enough time will be present before south winds
develop towards dawn that temperatures should quickly fall into
the 50s to around 60. Near Lake Champlain may remain warm now
that surface waters are much warmer in the lower 60s. Our
perennial cold spot at the Adirondack Airport appears likely to
fall into the upper 40s. Given the rain and good radiational
cooling, fog across our river valleys is expected.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 310 PM EDT Saturday...Ridging builds in for Monday and surface
high pressure centered near Bermuda will be the main influencer of
the weather. The associated southwest flow will advect much warmer
and gradually more humid air into the region. High temperatures will
be in the mid 80s to low 90s but thankfully the highest humidity
will be delayed until Tuesday. Dew points should remain in the low
to mid 60s. A prefrontal trough moves through Monday night into
Tuesday morning and it will set off a round of convection. There
should be some embedded thunderstorms but the instability during
this event looks to be elevated. Another round of showers and storms
is expected in the afternoon and there is the potential for stronger
storms if there can be clearing and destabilization before it
arrives. Dew points should already be in the low 70s. However, there
is no well-defined surface front/convergence, the mid level lapse
rates will be relatively shallow and resemble a moist adiabatic
profile, and there will likely be some clouds and showers around to
prevent efficient destabilization. Despite these inhibiting factors,
there will be plenty of shear and with the warm sector already in
place, it would probably not take much in the way of heating to
cause a stronger storm or two. The cooler and drier air gradually
filters in Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 310 PM EDT Saturday...A deep trough pushes into the region for
the middle of the week, bringing cooler conditions. A shortwave
pivots around this feature on Thursday and brings a pocket of
anomalously cold air aloft. The combination of the synoptic forcing
and solar heating on Thursday looks to cause widespread shower
development. The showers should diminish Thursday night as the
shortwave passes to the east and the diurnal heating ends. Surface
high pressure builds in for Friday and and looks to bring pleasant
weather for the start of the holiday weekend. Temperatures aloft
will warm pretty quickly but surface temperatures should still be
around or slightly below climatological normals. The humidity will
also remain low, with forecast dew points in the 50s for most
places. Shower chances increase for the latter part of the
weekend.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
Through 00Z Monday...Surface cold front moving ewd across nrn NY
at 2330Z is associated with just isold -RW activity; not
expecting precipitation at most of the TAF locations this
evening, but did include a PROB30 at KRUT/KEFK where best chance
for a brief shower exists. Otherwise, looking for VFR conditions
until roughly 04Z Sunday. After 04Z Sunday, post-frontal
stratus may create BKN-OVC020-030 thru mid-morning on Sunday
with HIR TRRN OBSCD. Appears moisture within frontal inversion
will gradual lessen, and this should allow for a trend toward
VFR and just SCT040-060 clouds for the late morning and through
the remainder of the TAF period. South winds this evening
becoming SW and W following frontal passage, with speeds
generally 5-10kt. May see a brief period of gusts 15-20 kts for
a 1-3 hour period following the frontal passage late this
evening.

Outlook...

Sunday Night: VFR. Patchy BR.
Monday: VFR. NO SIG WX.
Monday Night: VFR. Chance SHRA, Slight chance TSRA.
Tuesday: Mainly VFR, with areas MVFR possible. Definite SHRA,
Slight chance TSRA.
Tuesday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. Slight chance SHRA.
Thursday: VFR. Chance SHRA, Slight chance TSRA.
-- End Changed Discussion --

&&

.MARINE...
A Lake Wind Advisory remains in effect over Lake Champlain.
Wind speeds are gradually declining, but gusts up to 25 knots
continue to periodically occur. Waves are likely falling towards
2-4 feet waves across the broad lake at this time.

&&

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

&&

$$
SYNOPSIS...Haynes
NEAR TERM...Danzig/Haynes
SHORT TERM...Myskowski
LONG TERM...Myskowski
AVIATION...Banacos
MARINE...NWS BTV