794
FXUS61 KBTV 040728
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
328 AM EDT Thu Jul 4 2024

.SYNOPSIS...
A weak surface boundary moving through the region this morning will
exit east today with dry and seasonably warm conditions expected for
our Independence Day. Dry and warm weather continues Friday with a
very isolated shower or thunderstorm possible, before unsettled
weather returns for Friday night through Saturday with numerous
showers likely and a chance for thunderstorms. Dry weather returns
Sunday and continues into early next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 327 AM EDT Thursday...The forecast continues to play out nicely
with a weak surface boundary draped across northern/central portions
of the region this morning providing some widely scattered showers.
As the boundary shifts east, much drier mid/upper level air will
filter in, as evident on current satellite imagery, so expecting
after 8 AM the entire forecast area should be dry for the remainder
of the day with partly sunny skies developing. Behind the boundary,
the airmass doesn`t change much at all, hence why we`re not calling
it a front, with 925mb temps warmer than yesterday supporting highs
once again above normal in the mid/upper 80s. Humidity won`t be off
the charts, but dewpoints will hold in the lower 60s so it will be
just a little sticky, especially with winds tapering to light SSW
through the afternoon.

Another mild night is expected tonight with variable cloud cover
around, but mainly partly cloudy to mostly clear at times. Winds
will become light, and temps will only fall into the 60s with
locally close to 70 in the Champlain and St. Lawrence Valleys. Dry
weather generally prevails for Friday as well, but continued warmth
and slightly increased humidity combined with an approaching warm
front may spark some isolated terrain or lake breeze driven showers
and thunderstorms in the afternoon. Highs will once again be in the
mid/upper 80s with 90 possible at KBTV, and dewpoints will rise a
bit into the mid 60s supporting a moderate heat risk for those
individuals sensitive to heat.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
As of 327 AM EDT Thursday...Scattered thunderstorms with embedded
localized downpours are possible overnight Friday into Saturday as
an occluded front associated with a vertically stacked upper low
moves across the area. PWATs are forecast to rise to near 2.0
inches, which is at maximum of SPC sounding climatology for the
Albany, NY upper air site. A silver lining is that the dynamics
across our area is not all that impressive, so right now the
thinking is that we could get some garden variety storms with
generally manageable rainfall. Nonetheless, we will be monitoring
the heavy rainfall potential closely as we get further into the CAM
time range given how anomalously moist the air mass is. Overnight
temperatures on Friday night will not fall all that much. Aside from
upper 50s to low 60s in the typically cooler hollows, the Champlain
and St Lawrence valleys should see lows in the mid to upper 60s.

The occluded front is unlikely to result in an air mass change.
925mb temperatures fall briefly into the +19 to +21C range by the
latter half of the Friday overnight hours but rebound to +22 to +24C
during the day on Saturday. There could be more chances for showers
and thunderstorms on Saturday but the coverage and timing of the
storms remain in question at this time. Highs on Saturday look to be
near or just above climatological normal, in the low to mid 80s.
However, dew points in the mid 60s to low 70s would make it feel
more like the upper 80s to mid 90s in terms of apparent
temperatures. As such, the experimental WPC heat risk depicts
pockets of moderate heat-related impacts for portions of the
Champlain and St Lawrence valleys.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 327 AM EDT Thursday...By Saturday night, high pressure builds
in from the Ohio Valley along with the advection of a drier and
cooler air mass. A weak shortwave trough crossing the region on
Sunday could spark some scattered showers, but if one has to pick,
Sunday looks to be the nicer day of the weekend at this time.
Surface high moves overhead on Monday, which should be the a
pleasant day for outdoor activities with comfortable humidity.
Ensemble guidance shows increased probabilities for a shortwave
trough to approach the area in the mid week time frame, so once
again rainfall and thunderstorm chances will be on the increase.
However, given that we remain 5 days out, have kept with 30-40
percent PoPs for Tuesday onwards. The good news is that there are no
real signs of anomalous heat or flooding risk.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
Through 06Z Friday...Mainly VFR conditions are expected through
the period with local MVFR at KMSS and KSLK through 09-12Z.
Otherwise, scattered showers through 12Z may briefly reduce vsby
to MVFR/IFR but too difficult to forecast explicitly so just
mentioned VCSH. After 12Z, BKN ceilings lift to SCT for the
remainder of the period, continuing as VFR. Winds will also
lower significantly through the period, only gusting above 20kts
at KBTV through about 08Z, then lowering to 6kts or less after
12Z from the SSW. Areas of LLWS additionally shift east of the
region by sunrise.

Outlook...

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

&&

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

&&

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