796
FXUS61 KCTP 011123
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
723 AM EDT Mon Jul 1 2024

.SYNOPSIS...
A large high pressure system will build into the region today,
followed by a dying cold front pushing in from the Great Lakes
and stalling out over the area by the middle of next week. very
warm and quite humid air will return for the second half of this
week and last into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure (1026 mb or +2 Sigma) builds into the region today
and tonight, before sliding to the Mid Atlantic Coast by Tuesday
Evening.

Much drier air advecting into the region early this morning
via a light to moderately gusty (mid to upper teens - mph) NNW
wind - with a rare touch of Lake Effect clouds and some very
light rain/drizzle at times near the PA/NY border from the
relatively shallow, yet still quite extensive strato cu clouds.

Lake Erie water temps - 850 mb readings far exceed the required
13C needed for Lake Effect clouds and precip. This morning we
have Lake Erie temps along the south shore averaging around 72F
or 22C with 850 mb temps around 3-4C for a huge Lake/Air Delta
T of 18-19C.

Drier air will quickly mix down and erode the bkn-ovc clouds
streaming south across the Northern Mtns and Laurel Highlands.

Look for a mostly sunny to sunny late morning and afternoon with
excellent visibility and PWAT Values ranging from about 0.5 of
an inch in the West to 0.7 of an inch in the East.

Winds will gradually diminish this afternoon and go nearly calm
tonight as the center of high pressure (1025 mb or +2-3 sigma)
become centered across Upstate NY and Northern PA.

Strong radiational cooling early tonight will result in temps
far exceeding air water delta Ts of 20F, which will lead to
fairly widespread 1/2SM (or below) vsbys throughout the valleys
of northern PA, with patchy 1-3Sm fog throughout the Central
Valleys.

Mins tonight will slide into the mid and upper 40s over the
northern and western high terrain, and 50 to 55 respectively
throughout the Central and Southern Valleys.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
Sunny and several degrees warmer on Tuesday into at least the
first half of Wednesday, as upper level ridging builds over the
state and the aforementioned surface high drifts east and just
off the Mid Atlantic and Southern New England Coast.

Day-day high temp increases will be 5 to 8 deg F, bringing us
back to near or slightly above normal in the high temperature
category on Tuesday.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
An Upper Level Ridge will drift east form the Central US and
help to maintain fairly good amplification until Wednesday
night/Thursday when a weakening shortwave passes well north of
PA late Wed into Thursday and causes heights to sag up to a few
DAM.

The dying cold front is likely to sag into the state Thursday
and stall out in the vicinity of PA through Friday.

Falling heights/surging low level moisture ahead of the front
could support scattered convection as early as Wednesday
afternoon over the northwest half of PA. However, a better
chance of showers/tsra areawide will come with the arrival of
the front Thu into Friday. Early best guess of late week
rainfall based on ensemble plumes ranges from 0.25 to 0.75
inches, with the highest amounts over the N Mtns and least in
the south.

Heat and humidity should peak ahead of the front Wed-Thu.
Ensemble mean 850mb temps surging to near 20C indicate max temps
could reach the low to perhaps mid 90s in the Lower Susq Valley
Thursday, with high humidity pushing heat indices into the mid
and upper 90s.

Ensemble plumes suggest slightly cooler daytime temps late in
the week, due to more clouds and scattered mainly afternoon and
early evening showers and TSRA. However, high pwats in the
vicinity of the stalling front should result in warm and humid
days followed by muggy nights and above normal min temps the
entire second half of this week.

Models begin to diverge as we head into the weekend. Most
guidance suggests that rain chances stick around through at
least Saturday as another cold front approaches the area.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
MVFR cigs persist over portions of central PA with residual
moisture trapped beneath a low level inversion. Mixing of much
drier air aloft should cause any early stratocu to dissipate by
mid- late morning, with widespread VFR conditions expected the
rest of the day. A fairly tight pressure gradient should result
in gusty north winds for much of the day with gusts in the
20-25kt range for most of the region. Expect winds to diminish
toward evening, as the center of the high pressure system pushes
into PA.

Outlook...

Tue...Patchy AM valley fog N Mtns.

Wed...Evening tsra impacts possible NW Mtns.

Thu...AM low cigs possible W Mtns. Sct PM tsra impacts
possible.

Fri...Sct tsra impacts possible, mainly PM.

&&

.CLIMATE...
June 2024 was the warmest June on record for Bradford with a
mean temperature of 66.6F, breaking the old record of 65.8F set
in 2021.

June 2024 was the 3rd warmest June on record for Harrisburg with
a mean temperature of 76.0F.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Lambert
NEAR TERM...Lambert
SHORT TERM...Lambert/Dangelo
LONG TERM...Lambert/Bauco
AVIATION...Fitzgerald/Colbert
CLIMATE...Colbert