-- Discussion containing changed information from previous version are highlighted. --
620
FXUS61 KBTV 252335
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
735 PM EDT Sat May 25 2024

.SYNOPSIS...
A few showers and a possible embedded thunderstorm will pass through
tonight. Drier and warmer weather will move in for Sunday as high
pressure briefly returns. Rain showers will gradually overspread the
region on Memorial Day and last into Tuesday. Behind the storm,
cooler weather will prevail for mid to late week.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 330 PM EDT Saturday...Clouds are increasing this afternoon and
rain showers will arrive this evening. These will be from a dying
occluded front that will make its way through the region. The
steadiest rain will pass by to the south and it will mostly be some
scattered showers here. Some elevated instability will develop
overnight and a couple of the showers may contain some thunder, but
they will generally be unimpressive. QPF will mostly be under a
tenth of an inch but the areas that see the convective showers will
see a little more. The showers will move out later in the night and
partial clearing will occur. With light winds and plentiful low-
level moisture from the rain in place, patchy fog should develop.

A warmer and slightly more humid airmass will move in behind the
front for Sunday. Temperatures will rise into the mid 70s to low 80s
and dew points will be in the 50s. Daytime heating could cause
isolated showers to develop, mainly over the high terrain and
southeast Vermont. Ridging will briefly build in for late Sunday and
Sunday night, and skies should gradually clear. The dry weather will
be short-lived though as rain showers will begin to enter the region
late Sunday night. These will be out ahead of a stronger area of low
pressure that will impact the region Monday-Tuesday. Winds will
shift to southeasterly and begin to strengthen later in the night.
Lows will therefore likely be during the middle of the night as the
winds will mix warm air down to the surface and strengthen warm-air
advection and likley cause temperatures to rise. Lows will overall
be mild, with temperatures only dropping into the mid 50s to lower
60s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
As of 330 PM EDT Saturday...A surface occlusion is expected to
develop across the region on Monday as low pressure matures across
the Great Lakes area. 40-50kt mid-level flow will transport warm,
moist air north. The combination of isentropic lift and weak
elevated instability will drive isolated showers with a few rumbles
of thunder. Abundant cloud cover will keep conditions a bit cooler,
but still on the warm side in addition to higher dewpoints move into
the area. Additionally, the increased mid-level flow will likely
yield some 20 to 30 mph gusts, locally up to 35 mph on Monday.

The bulk of precipitation will occur Monday evening into the
overnight when sharper surface confluence develops along the
occluded front. The front will be slow to progress east, but a jet
streak will approach to help force it east towards dawn on Tuesday
before it can really outstay its welcome. Areal extent will decrease
with the loss of daytime heating, but never completely diminish.
With the humid air mass, expect mainly mid 50s to lower 60s. The
front doesn`t quite clear Vermont until afternoon, and so showers
and storms could develop early before shifting out. Then showers
rotating within the upper low will reach St. Lawrence County as
well. The tongue of dry air associated with a dry slot will keep the
Champlain Valley and southern Vermont relatively dry on Tuesday.
Expect another seasonably warm day in the 70s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 330 PM EDT Saturday...Forecast guidance diverges fairly quickly
beyond Tuesday. The primary source of difference is how deep the
upper low is. The deeper it is, the slower the model wants to shift
it out of the region. Additional pop-up, hit-or-miss shower activity
will be present through the remainder of the week. Probabilistic
data currently suggests Friday and Saturday have lower chances for
precipitation, but as we head deeper into summer, their skill will
suffer as convection becomes more common place. However, the pattern
overall does not appear likely to be too wet heading into the
following week and CPC does forecast Day 6-10 as drier than normal
too. With general troughiness, it does appear that we will spend a
few days on the cooler side of normal for a few days. Expect mid 60s
for the midweek to trend back into the 70s by the weekend with 40s
to 50s overnight.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
Through 00Z Monday...Aviation focus will be on IFR potential
after 06z at SLK/MSS and MPV. Currently VFR at all sites with
some light rain showers moving from west to east. Additional
showers are possible through 06z, before subsidence/dry air
aloft develops with decreasing threat for rain showers. This
drying will help push moisture toward the surface with a
lowering cloud deck, especially at SLK with some intervals of
IFR vis/cigs possible. Have noted LAMP guidance suggesting fog
at with IFR at MSS, but confidence is lower with probability
<10%, so have used VCFG for now. Otherwise, feel a 10 to 15%
probability of fog/br with ifr is possible around sunrise at
MPV/EFK, but given the clouds and timing after 06z, have not
mention in tafs. Otherwise, VFR redevelops at all sites by 12z
with light trrn driven winds <6 knots prevail thru 00z Monday

Outlook...

Sunday Night: VFR. Slight chance SHRA.
Memorial Day: Mainly VFR, with areas MVFR possible. Chance SHRA,
Slight chance TSRA.
Monday Night: Mainly MVFR, with local IFR possible. Chance SHRA,
Slight chance TSRA.
Tuesday: Mainly VFR, with local IFR possible. Chance SHRA, Slight
chance TSRA.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: Mainly MVFR, with areas VFR possible. Chance SHRA.
Wednesday Night: Mainly MVFR, with local IFR possible. Chance
SHRA.
Thursday: MVFR/IFR conditions possible. Chance SHRA.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...Myskowski
NEAR TERM...Myskowski
SHORT TERM...Haynes
LONG TERM...Haynes
AVIATION...Taber