141
FXUS61 KBTV 061641
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1241 PM EDT Sat Jul 6 2024

.SYNOPSIS...
Numerous showers and thunderstorms will roll through the forecast
area this morning, with more hit or miss activity this afternoon
before dissipating after sunset. Drier days are forecast for Sunday
and Monday although remaining humid at the ground and warm. Another
round of showers and thunderstorms likely late Tuesday into
Wednesday along a cold front passage. Slightly cooler and less humid
air returns midweek.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 1236 PM EDT Saturday...Partial sunshine has broken out
across the region and temperatures have responded decently,
rising into the upper 70s and 80s. Scattered convection has
begun to develop, mostly across central Vermont. The trend will
continue and scattered showers and storms will be possible
anywhere this afternoon. Storms have been moving quick enough to
prevent flooding concerns but the areas to watch continue to be
the areas that have received 1+ inches of rain already this
morning. Previous discussion follows...

After all the morning convection passes after the noon hour, we
should see breaks of sunshine develop and with surface
dewpoints still well into the upper 60s to lower 70s instability
will grow with progged SBCAPE`s in the 1000-1500 J/kg range. A
weak cold front to our west and some embedded shortwave energy
riding northeastward ahead of the parent upper trough over the
Great Lakes should provide the necessary lift to spark some
additional showers and thunderstorms in the afternoon, but
should be fairly widely scattered. Some storms could become
strong, though as the previous forecaster mentioned, the
presence of some mid- level dry air and 50-60kts of 0-6km shear
may hamper updraft development. Certainly areas to watch for
isolated flash flooding will be where the greatest rainfall
footprints are from the morning convection, which will likely be
across Rutland, Windsor, and Orange counties.

Convection generally dissipates after sunset but with the frontal
passage not expected until after midnight, the warm and humid
airmass will likely support some isolated showers and perhaps some
embedded thunder through the first half of the overnight. Drier
conditions generally follow for Sunday though a weak boundary north
of the border may help to spark some isolated showers across border
towns. Not enough to cancel any outdoor plans for sure, but temps
will once again be rising into the mid/upper 80s and dewpoints
remain in the 60s producing a moderate heat risk for some VT locales.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 351 AM EDT Saturday...Sunday night should be cooler than of
late, with mostly clear skies and light winds promoting good
radiational cooling. Some of the colder hollows could see lows in
the lower 50s with upper 50s to low 60s for many locations. Warmest
spots would once again be across the urban centers of the Champlain
valley with lows in the mid 60s. Surface high pressure moves
overhead on Monday, which should prove to be a decent day for
outdoor activities with comfortable humidity. Temperatures will once
again peak in the mid 80s to near 90, but with mixing up to
850-800mb, lower dew points should be mixed down to the surface so
expect plentiful sunshine with breezy southwest winds helping to
make being outdoors rather pleasant for the North Country in mid
July. By Monday night, winds will shift to the south as an upper
level disturbance approaches from the Great Lake with overnight lows
generally in the 60s.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 351 AM EDT Saturday...Upper ridging starts to break down on
Tuesday as a positively tilted upper level trough approaches from
the Great Lakes. As such, shower and thunderstorm chances do return
on Tuesday. NAEFS ensemble situational awareness table shows PWATs
and IVT rising to over 90th percentile for our region later Tuesday
into Wednesday, so multiple rounds of heavy rainfall is certainly
possible with a slow-moving cold front nearby providing the focus
for scattered to numerous thunderstorms. Looking upstream, the
anomalous PWAT plume appears to have its origins in the Gulf of
Mexico. The orientation of the approaching upper trough does allow
for the possibility of TC Beryl- related moisture to stream towards
the Northeast. PWATs rise to around 2 inches on Tuesday with some
deterministic guidance even showing upwards of 2.3 to 2.5 inches.
For reference, the daily max of climatology for Albany, NY upper air
site around mid July is around 2.1 inches. Fortunately for our area,
the consensus of guidance shunts the plume of richest PWATs south of
our area later Tuesday into early Wednesday. There are indications
that the unusually moist air mass could coincide with the better
dynamics for stronger storms that would further enhance the
rainfall, but mid- range guidance still unsurprisingly differ on the
timing of the surface cold front. Right now, WPC has continued to
highlight a marginal risk for excessive rainfall for Day 4 (Tuesday
into Tuesday night) across the entire CWA but not Day 5 (Wednesday
into Wednesday night). Those with outdoor plans middle of next week
are advised to stay up to date with the latest forecast.

Additionally, if drier weather were to prevail, parts of the
Champlain valley and Connecticut valley could see heat index values
rise into the lower and mid 90s. WPC heat risk does highlight
potential for widespread moderate heat-related impacts for Tuesday
so the temperature trends are worth monitoring as well in addition
to heavy rainfall and thunderstorms. Cold front should finally clear
the region later Wednesday into Thursday, leading to at least a
couple of days with more seasonable temperatures (upper 70s to mid
80s) and comfortable humidity (dew points in the 50s) for mid July
standards. Having said that, the aforementioned plume of tropical
enhanced moisture continues to linger across the Mid Atlantic states
into Southern New England. By Friday, a warm front may be lifting
northwards again and we might once again get into the more humid if
not oppressive air mass. Stay tuned.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Through 12Z Sunday...Lingering low clouds from overnight
convection across central/northern areas will be lifting to VFR
within the next couple of hours, with a brief period of MVFR/IFR
likely at KRUT as remnants of another convective complex shifts
through. After 15Z, isolated showers and thunderstorms are
possible through the afternoon, but confidence on hitting a
terminal is low so have only included VCSH. After 00Z,
convective wanes and skies should trend clearer, but this opens
the door for IFR fog to develop. Best chance of occurrence is
at KSLK, KMPV, and KEFK.

Outlook...

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

&&

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

&&

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