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715
FXUS61 KCTP 102343
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
743 PM EDT Thu Jul 10 2025

.SYNOPSIS...
* Continued seasonably warm and humid with near to above normal
  temperatures into mid July
* Daily doses of drenching thunderstorm downpours capable of
  producing isolated wind damage today (Thursday) and Friday
* Episodes of rain continue this weekend into early next week
  with the strongest wet signals on Sunday and Monday

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Thunderstorms have developed downstream of Lake Erie along lake
breeze boundaries and will continue to move into northwest PA
through the rest of the afternoon and evening. SPC mesoanalysis
shows that there is around 1500 J/kg of CAPE available for these
storms to work with, but modest mid-level lapse rates and
relatively weak shear (generally less than 25 knots) should
limit how strong these storms get. Still, SPC has maintained the
marginal risk of severe weather over the northern tier and a few
damaging wind gusts cannot be completely ruled out. While
northern PA will be the focus for convection today, an isolated
shower or storm will be possible anywhere in the region.

Thunderstorms will quickly come to an end with the loss of
daytime heating later this evening and skies will clear out,
allowing for fairly widespread fog formation tonight.Model RH
profiles suggest that the northwest mountains and portions of
the Lower Susquehanna Valley have the highest probability for
fog formation with a relative minimum in between those areas.
Low temperatures tonight will range from the low 60s over the
Alleghenies to the low 70s in the southeast.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Despite the absence of a pronounced focusing/triggering
mechanism for CI, diurnal heating of a seasonably warm, moist
and weakly capped airmass will result in more isolated to
scattered afternoon thunderstorms Friday into the weekend.
Although precipitable water values look to trend lower vs.
previous days, there will still be at least a marginal risk for
a few water-loaded downbursts and localized heavy rainfall.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Wet signal strength likely peaks Sunday into Monday which
appears tied to a frontal system progressing eastward from the
Great Lakes and Ohio Valley through CPA. There will be at least
some potential for strong to severe thunderstorms as this system
moves through, with ensembles showing moderate instability
developing. Confidence is low, however, on the exact timing of
any storms.

There is increasing confidence in a 48hr break in the rainy
summer pattern next Tuesday and Wednesday. This "dry" signal is
reflected in the latest medium range models and ensemble
guidance which shows sfc high pressure/upper level ridge moving
into the area in the wake of the aforementioned frontal system.
Temperatures will remain firmly in summer mode trending near to
above (+5-10F) the historical average moving into 2H of July.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
Any remaining -SHRA or -TSRA are diminishing as they move
generally north of a Stoneyfork VOR to Keating VOR line. I
expect these to diminish entirely through sunset as they are
moving into an area that has been worked over the past few days
with convection, and loss of daytime heating.

Overnight, clearing skies and calm winds will support
visiblity rstriction in BR/FG across the region. The best
chance for IFR cigs/vis will be in northwest PA (KBFD) and
southeast PA (KMDT and KLNS) from fog/low ceilings. MVFR
restrictions are possible for a few hours at JST, AOO, and UNV
as well, though confidence is lower there. IPT will see MVFR
restrictions and IFR restrictions are possible. Chance for IFR
cigs/vis run about 30% in the central swath of airfields, rising
to >70% on the bookends northwest and southeast.

Improving conditions on Friday morning will precede more
afternoon shower/thunderstorm development. Specific location
uncertianty this far out will preclude mentioning in any one
site but will add as locations become more certain.

Outlook...

Sat...Scattered afternoon/evening storms, mainly south.

Sun...More widespread showers/storms likely.

Mon...Still storms around.
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&&

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

&&

$$

SYNOPSIS...Steinbugl/Bauco
NEAR TERM...Bauco
SHORT TERM...Steinbugl/Bauco
LONG TERM...Colbert/Bauco
AVIATION...Banghoff/Tyburski