000
FXUS61 KBTV 200548
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
148 AM EDT Sat Apr 20 2024

.SYNOPSIS...
Scattered showers and breezy conditions will continue this evening
into Saturday. Although Sunday and Monday will trend drier, it will
be unseasonably cool, especially Monday. Temperatures will begin to
moderate on Tuesday, with rain chances increasing over the middle of
the week.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 127 AM EDT Saturday...

No major changes were needed with this forecast update. The
breezier winds from earlier this evening have lightened some,
with most places seeing wind speeds 10 mph or less. Temperatures
have remained very steady this evening, currently in the mid 40s
to low 50s. Main change was to adjust overnight temperatures to
reflect the latest observations.

PREVIOUS DISCUSSION...

A weakening occluded front is currently sliding east. Some
sprinkles are making it to the ground here in the northern
Champlain Valley, but the bulk of precipitation resides in
northern New York. Overall, still not looking at much in terms
of amounts at about 0.10" or less, and generally favoring
northern New York. Temperatures are just slightly below season
normals across the region, with 50s and even some spot 40s.
Winds have been breezy, although not gusting too much. Later
this evening, a low-level jet will maximize over the area,
channeled mainly across the Champlain Valley. About 6 PM to 10
PM, we could see some brief 30 to 40 mph gusts along Lake
Champlain, before trending back down to the 15 to 25 mph it has
been most of the day.

Negative thickness advection and the upper trough pivot into the
region overnight. Along the boundary, there could be a brief
resurgence of precipitation from the southwest that will generally
stream along the Connecticut River Valley, but some guidance has
some light rain making it as far north as the northern Champlain
Valley. Overall, additional precipitation should again be light.
Abundant clouds and south flow will keep temperatures warm
overnight, with mid 30s to mid 40s.

On Saturday, we`re still poised for a very strong upper trough to
pull some moisture off Lake Ontario to produce conditional
instability across the region. Model progged CAPE of 150 to 250 J/kg
with steep lapse rates should produce scattered showers, especially
across the St. Lawrence Valley and northern Vermont. Low-level
conditions will be dry, and showers could drive gusty winds up to 35
mph to the surface, while background flow remains about 15 to 25
mph. With such cold temperatures aloft and potential for evaporative
cooling, some of these showers will produce pea sized hail or
graupel. The greatest concentration of activity will be over
northern New York and far northern Vermont, which will lead to
cooler high temperatures in the mid 40s to around 50. In the lower
Champlain Valley and Connecticut River Valley, fewer showers should
allow temperatures to warm into the mid to upper 50s. Shower
activity will decline after sunset and the vort max shifting east
overnight. Despite lack of clearing, the cold advection should drive
temperatures just below seasonal normals, with mid 20s to mid 30s.

&&

.SHORT TERM /SUNDAY NIGHT/...
As of 344 PM EDT Friday...A couple of waves will be moving through
Sunday and Sunday night. The first will be weak since best forcing
remains in northeastern Canada; potential for isolated showers will
be limited mainly to locations towards the Canadian border. More
notably, the pressure gradient will be tightening through the day
supporting increasing winds as a sharper front moves through
overnight. Southwest gusts 20 to 35 mph will be possible late
afternoon through the evening. The sharper cold front overnight will
be mostly dry for central/southern Vermont and Essex County of New
York, but will bring 10-40% chances of low elevation rain showers
and snow showers for elevations above 1800 feet. Cold air advection
will be ample with overnight lows dipping below freezing into the
20s for the Adirondacks/northeaster Vermont and upper 20s/low 30s
elsewhere. As such, wind chills will be in the teens to 20s; quite a
departure from recent relative warmth.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 344 PM EDT Friday...Model guidance continues to favor a
progressive upper level pattern with passing ridge/troughs swinging
temperatures widely. Portrayal of the mid week low continues to show
robust development with strong warm air advection on Tuesday,
potentially into the mid/upper 60s, followed by widespread freezing
overnight lows Wednesday and Thursday nights. While below seasonal
averages, the anomalies for temperatures are generally around to
less than 1 standard deviation which is not obscenely unusual for
this time of year. The projected evolution of the low suggests
potential for gusty winds associated with a strong low level jet
which should be sufficient for gusts 20- 30 mph for most spots with
channeled areas approaching 40mph. Fortunately, the upper pattern
remains progressive enough to keep widespread heavy rainfall chances
limited - still estimated to be generally less than 0.5"; can`t rule
out some thunderstorms ahead of the frontal boundary, but those
details will become better known over the next 24 hours when we move
into mesoscale model time windows. With the low exiting by Friday,
shower chances will diminish except some lingering upslope showers
remaining possible. Heights will be rising, however, so temperatures
should be trending back towards seasonal averages.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Through 06Z Sunday...Currently a mix of MVFR and VFR flight
conditions across terminals with current ceilings between 2500
to 5000 ft AGL. Ceilings should trend towards VFR by morning as
any lingering scattered showers come to an end. A period of VCSH
will be possible tomorrow evening, however some additional
showers will develop in the afternoon (particularly across
northern terminals). Gusty winds for earlier this evening will
abate for the next several hours and become more westerly, but
will pick up again between 15Z to 18Z, with gusts up to 20 knots
possible tomorrow afternoon. Some areas of LLWS continue to be
possible for the next few hours across the forecast area.

Outlook...

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

&&

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

&&

$$
SYNOPSIS...Haynes
NEAR TERM...Haynes/Kremer
SHORT TERM...Boyd
LONG TERM...Boyd
AVIATION...Kremer