555
FXUS61 KCTP 051841
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
241 PM EDT Fri Jul 5 2024

.SYNOPSIS...
*Very warm and humid summertime pattern with above average
 temperatures continues into next week
*Showers and thunderstorms are possible in spots today and
 Saturday followed by a rain-free end to the first weekend of
 July

&&

.NEAR TERM /THROUGH TONIGHT/...
Mesoanalysis shows broad but light cyclonic flow around a weak
sfc low (1007 mb) located between KUNV and KIPT. This low was
along an ill-defined, quasi stnry front near the I-80 corridor
with a weak, lee-trough extending down through the Mid and
Lower Susq Mainstem.

Rich moisture with PWAT values between 1.5 and 1.9 inches across
all but the Western Mtns of our CWA topped by sharp mid level
ridging and a notable mid level cap with 700 mb temps of +9-11C
has led to a mostly cloudy to cloudy morning so far with very
little precip of note other than some stray light showers.

We should see breaks in the cloud area slowly develop during the
mid to late afternoon with isolated to widely sctd showers/TSRA
developing, mainly across the Western Mtns.

Convection will continue to form/advect from the west late today
through early tonight (similar to the evening of the 4th, but
perhaps just a bit greater in areal coverage).

Previous...

The latest hires guidance continues to favor a suppressed
convective scenario for today - leaning bearish for t-storms and
potential severe risk - with very limited development through
the afternoon and into the evening hours. Early day cloud cover
and shower activity (leading to reduced instability) appear to
be the primary contributors. CAM signal remains consistent in
ramping POPs higher across the NW zones closer to 00Z.

CAPE and shear profiles are supportive of isolated severe
t-storm potential with a large MRGL risk SWO covering most of
the CWA. However, timing remains a wildcard and could end up
being to late in the day/after dark.

Another hot and humid summer day across CPA with highs in the
85-95F range. With the humidity (dewpoints 70-75F), it will feel
like 100-102 degrees across portions of south central PA
particularly in the lower Susquehanna Valley. Max HX values
ticked higher above the century mark and we coordinated with
WFO PHI on the issuance of heat advisory from noon to 8PM. A
couple of showers/t-storm will could linger overnight which
will be very warm and muggy with low temps 65-75F.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Focus for t-storms will shift to the eastern periphery of the
CWA on Saturday PM along and ahead of a weak cold front. Despite
a very moist/unstable environment, most model guidance suggests
limited storm coverage likely owing to neutral height falls and
weak llvl convergence. That said, still can`t rule out a couple
of strong t-storms over eastern PA.

High pressure builds in Saturday night and provides a slightly
less humid and dry (rain-free) end to the first weekend of July.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Diurnally driven showers and thunderstorms appear possible on
Monday with easterly/southeasterly flow bringing an increase of
moisture to central Pennsylvania. Surging PWATs into Tuesday
will promote higher chances of precipitation later in the
evening and into Wednesday morning as a surface cold front
approaches the region. Precipitation is expected to continue
through late Wednesday when the cold front shifts east of the
area, but have retained PoPs through the end of the Wednesday
timeframe based on some remaining uncertainty with regards to
timing.

Some divergence in model solutions on Thursday and into the end
of the week with the North American suite of models outlining
surface high pressure taking hold across the region while the
European suite of models outline a continuation of showers and
storms throughout the period, so have capped chances to SChc
outside of peak daytime heating hours where slightly higher
probabilities emerge.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
LLVL moisture pooling around a weak area of low pressure
centered over the West Branch of the Susquehanna at midday will
continue to create plenty of clouds through early this afternoon
with areas of stubborn MVFR. Conditions will gradually improve
to VFR in most places after 18Z.

Isolated to scattered showers and thunderstorms will be
possible again later this afternoon, though coverage looks to be
initially more limited than what occurred Thursday.

VFR will likely persist through much of tonight with the only
restrictions coming in the form of a scattered shower or
thunderstorm. Lower cigs could reintroduce restrictions by
Saturday morning.

Outlook...

Fri...Sct TSRA w/ possible impacts; Mainly PM w/ highest
coverage across the west.

Sat...Sct to Nmrs TSRA areawide, highest chances SE in PM.

Sun...AM fog possible; otherwise, no sig wx.

Mon...SHRA possible SE late PM; otherwise, no sig wx.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT this evening for PAZ026>028-035.
Heat Advisory until 8 PM EDT Saturday for PAZ036-056-057-059-
063>066.

&&

$$

SYNOPSIS...Lambert/Steinbugl
NEAR TERM...Lambert/Steinbugl
SHORT TERM...Steinbugl
LONG TERM...NPB
AVIATION...Lambert/Bauco/Bowen