032
FXUS61 KBTV 080258
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1058 PM EDT Fri Jun 7 2024

.SYNOPSIS...
Upper level low pressure will control the regions weather through
Monday with scattered to numerous diurnal showers each day, along
with a slight chance for thunderstorms. Drier conditions return mid-
week, but turn unsettled again towards Friday.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 1040 PM EDT Friday...Thunderstorm activity has waned
significantly with the loss of daytime heating and the
environment being worked over multiple times. Despite relatively
unimpressive overall synoptics, the cold pool aloft and
relatively steep mid-level lapse rates led to numerous
convective showers this afternoon. We even had a severe-warned
storm that produced half dollar sized hail in Addison County.
Otherwise, there are currently no warnings or SPS in effect. The
only thunderstorm of note is one that is currently moving
northeastward along the Connecticut River between Essex county
in VT and Coos county in NH. There was also some lightning
activity over Lake Memphremagog north of Newport, but that has
since moved on into Quebec. SPC mesoanalysis shows a few hundred
joules of CAPE over northeast VT into NH, and that is colocated
with the favorable left exit region of an 80 kt jet streak. That
feature is expected to move east of the region after midnight,
so have kept the mention of thunder across the eastern third of
our CWA for a few more hours. Otherwise, it would be a
relatively quiet night with isolated to widely scattered
showers. It would also be a cooler night than of late, as a
broad H5 low continues to meander just south of James Bay,
advecting cooler air into the region as 925mb temperatures fall
from +14C to +11C overnight tonight.

PREVIOUS DISCUSSION...As expected, the leading shortwave on the
edge of an incoming cold upper low produced numerous showers
and thunderstorms across the region today. The strongest cores
developed in the Champlain Valley where several reports of pea
to dime/penny size hail were received, and a few stations saw
gusts upwards of 30-35 mph. Small footprints of heavy rain were
noted as well, with one prompting the issuance of an areal flood
warning in the Enosburg Falls area. Convective activity is
already beginning to wane, with the last strong cores shifting
north of the international border. Showers and isolated thunder
will likely linger across the Northeast Kingdom this evening,
but conditions should trend calmer for the overnight hours as
the upper low centers overhead.

With the upper low centered over the region on Saturday, the threat
for additional diurnally driven showers exists, though should be
less in areal coverage and the threat for thunderstorms is much
lower, maybe 10%, not enough to explicitly mention in the forecast.
And much like today, showers will decrease in coverage after sunset
with the loss of surface heating but our next shortwave will be
arriving early Sunday morning so only a brief break in the action is
expected. More on that below.

&&

.SHORT TERM /SUNDAY NIGHT/...
As of 307 PM EDT Friday...Upper low circulation will continue to be
the focal point for showers and isolated thunderstorms Sunday as a
trough pinwheels around the low through the North Country. With
lower heights under the cold pool aloft, small hail with
thunderstorms will be a reasonable assumption. Surface temperatures
will be running on the cooler side of seasonal averages, generally
in the mid 60s to low 70s, so instability will be more limited with
primary forcing associated with the trough itself. Model most
unstable Cape does support a few moderate strength updrafts giving
further credence to small hail potential. QPF will be highly
variable, but synoptic forcing and PWATs favor totals capped around
0.5" outside any more strongly forced cells. Most likely wave timing
will have convection occurring early Sunday through mid Sunday
afternoon. Overnight, chances diminish with lows around seasonal
averages in the mid 40s to mid 50s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 307 PM EDT Friday...The probability of a stagnant longwave
pattern continues to be high for the beginning of next week with
ensembles supportive of continued rounds of showers under a cutoff
low circulation. Temperatures will remain around seasonal averages
under this pattern. After Tuesday, conditions become more favorable
for longwave movement with high pressure and a marked warming trend
becoming more probable. Deterministic models are more limited in the
amplitude of the ridge, but ensembles highlight a decent probability
of high temperatures increasing into the mid/upper 80s for the
second half of next week.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Through 00Z Sunday... VFR conditions generally prevail through
the TAF period. Afternoon thunderstorms have generally waned
except VCTS through 04z for KBTV and KEFK. A period of MVFR
ceilings is possible at KMPV/KSLK/KMSS tonight between 06z and
12z. VFR and isolated to scattered showers return after sunrise
Saturday, but are not expected to result in a reduction in
visibility or ceilings below VFR. Winds will generally be
southwest at less than 10kts through Saturday 12z, before
turning south- southwest or westerly with gusts up to 20 kt at
times after Saturday 15z.

Outlook...

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

&&

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

&&

$$
SYNOPSIS...Lahiff
NEAR TERM...Chai/Lahiff
SHORT TERM...Boyd
LONG TERM...Boyd
AVIATION...Chai