858
FXUS61 KBTV 021449
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1049 AM EDT Thu May 2 2024

.SYNOPSIS...
Scattered to numerous showers, with a few possible thunderstorms,
will continue through the day today over northern areas. High
pressure will return for Friday and bring drier weather and some
breaks in the sun. Rain showers enter northern New York on Saturday
and the entire region for Sunday. Drier weather looks to start next
week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 1049 AM EDT Thursday... Some adjustments to temperatures,
PoPs, and sky cover were made this morning, but overall
forecast is in good shape. Interesting weather scenario in place
with a weak cold front bisecting our region. Based on surface
pressure analysis, the front is currently stretches from the far
northern Champlain Valley southwestward through the eastern
Adirondacks. Ahead of the front there is a sliver of surface-
based CAPE of up to 100 J/kg with effective shear of around 20
knots, and with further daytime heating values could approach
500 J/kg early this afternoon in eastern Vermont. As such, some
showers could grow tall enough to produce thunder but no strong
thunderstorms are expected. These showers will move
southeastward through mainly central and eastern Vermont this
afternoon. Behind the front there will be a lot of cloud cover
and cooler conditions streaming southward, associated with an
upper level low spinning to our north.


Previous Discussion...

A warm front is passing through the North Country tonight and
it is bringing some scattered showers and thunderstorms from an
area of elevated instability. These storms will continue for
much of the night before dissipating by mid- morning as the
elevated instability diminishes. Some showers will then develop
during the day across northern areas as a shortwave trough
builds into the region and an associated cold pool steepens
lapse rates. Diurnal heating will help create some surface based
instability, particularly over Northeast Vermont, and there is
the possibility that it is strong enough for a couple
thunderstorms to develop. Small hail and graupel cannot be ruled
out in these storms due to the cold air aloft. There is a
strong QPF gradient across the region with southern areas only
expected to see a few hundreths of an inch of rain while the
Northeast Kingdom should see up to around a half-inch. Across
the showery northern areas, temperatures will only reach the
lower 60s. However, temperatures will reach the upper 60s and
low 70s across southern Vermont where it will be drier and where
some breaks in the clouds are possible.

The shortwave passes to the east overnight and the shower chances
quickly end as lapse rates lower and diurnal heating ends. Abundant
low-level moisture and light winds could cause fog formation
overnight, particularly if some breaks form in the clouds.
Temperatures will fall into the 40s across the region. An upper
level ridge builds into the region on Friday and it will bring drier
and warmer weather. 925 mb temperatures look to rise to between 9-14
degrees but easterly flow will keep the warmest temperatures, up to
20 celsius, just to the southwest over Central New York. Highs
should therefore range in the upper 60s and low 70s. Temperatures
will depend a bit on how quickly the low clouds from Thursday`s
shortwave scour out and how quickly high clouds build in from the
west. It looks like there should at least be some filtered sunshine
during the day for most areas.

&&

.SHORT TERM /FRIDAY NIGHT/...
As of 408 AM EDT Thursday...Longwave ridge axis shifts eastward
Friday night with southerly flow increasing. Expect increasing cloud
cover and mild overnight temperatures in the mid/upper 40s and low
50s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 408 AM EDT Thursday...The pattern evolution will support deeper
moisture transport from the Gulf of Mexico Saturday as upper level
ridge axis amplifies downstream of the North Country. A weak trough
moving out of the lower mid west will help pull Gulf moisture
northward while a stronger trough with upper level support swings
through the Great Lakes region. These features will likely begin to
phase supporting PWATs in excess of 1" late Saturday into Sunday as
the surface trough moves through the region. Expect shower chances
to begin increasing Saturday with rain/rain showers Saturday night
and Sunday. While conditions will be wet, best forcing will likely
be displaced northward into Canada as the low rides up the ridge, so
excessive rainfall/flooding is not anticipated.

Active pattern continues with ridging returning Monday into Tuesday.
A lack of cold air replacement resulting from the nature of the
continental airmass from lower/central US Plains will keep
temperatures running warmer that seasonal averages. Ensembles favor
a pattern that would support highs in the lower/mid 70s. We`ll be
keeping an eye on the mid-week system that may move into the North
Country on Wednesday. Warmer temperatures and a chance at decent
forcing could supply ingredients for more robust thunderstorms. It
will all depend on timing which is vague this far out. Should a
front approach during max heating Wednesday, a few stronger storms
would be possible. However, it`s just as likely at this point that
frontal passage could be offset outside of peak heating which would
limit convection. Ensembles keep a progressive pattern beyond
Wednesday supporting quick moving ridge/troughs.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
Through 12Z Friday... Any lingering thunderstorms will exit the
region by 13Z. Scattered showers will return later in the morning
and continue through the afternoon, and an embedded thunderstorm is
possible at EFK. The showers and thunderstorm threat will end this
evening. There is currently a mix of flight categories at the
terminals but there should be slight improvement today where at
least every terminal reaches MVFR. However, low clouds will return
tonight and there is a possibility that ceilings at any terminal
could fall to IFR. Any breaks in the low clouds could also lead to
fog formation. However, confidence is not high on the forecast for
tonight yet. Winds will be relatively light during this period and
will generally switch to southwesterly. Winds shear should lower
below LLWS criteria this morning as a low-level jet exits the
region.

Outlook...

Friday: Mainly VFR, with local MVFR possible. NO SIG WX.
Friday Night: VFR. Slight chance SHRA.
Saturday: VFR. Chance SHRA.
Saturday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Sunday: Mainly MVFR, with areas VFR possible. Likely SHRA.
Sunday Night: Mainly IFR, with areas MVFR possible. Chance SHRA.
Monday: MVFR/IFR conditions possible. Slight chance SHRA.

&&

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

&&

$$
SYNOPSIS...Myskowski
NEAR TERM...Kutikoff/Myskowski
SHORT TERM...Boyd
LONG TERM...Boyd
AVIATION...Myskowski