442
FXUS61 KCTP 222340
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
740 PM EDT Fri Aug 22 2025

.SYNOPSIS...
* A warming trend begins today and continues into the weekend.
* Scattered strong thunderstorm potential on Sunday as a strong
  cold front sweeps through.
* Strong Canadian high pressure will bring a refreshing taste of
  Fall with cooler temperatures and lower humidity into the
  last week of August.

&&

.NEAR TERM /THROUGH SATURDAY/...
Today`s satellite imagery is rather striking with Erin racing
off to the northeast about 400 miles off the coast of Cape Cod
and tranquil weather across the northeast and midwest.
Subsidence to the west of Erin is producing mostly sunny skies
from Central PA northeast to Newfoundland. High pressure will
remain in control tonight with dry and pleasant conditions
continuing. Clear skies overhead will provide efficient
radiational cooling.

After sunset, any fair weather cumulus will collapse and give
way to a pleasant night. Dewpoints will tick up slightly
overnight, keeping lows a few degrees warmer than this morning.
Light wind, mainly clear skies and cool temps with an air/water
delta T around 20F will lead to areas of fog throughout the
deeper valleys of Northern PA before dawn once again tonight.
Lows by daybreak will generally be in the mid to upper 50s.

&&

.SHORT TERM /SATURDAY NIGHT/...
Increasing and moderately gusty southerly llvl flow (into the
teens and low 20s MPH) and a rise in sfc dewpoints by 5-7 deg F
on Saturday will mean more in the way of cu development. Sky
cover will still likely stay below 50 percent, so mostly sunny
conditions will be the case.

High temps Saturday afternoon will be similar if not a deg F or
so warmer than today (Friday). Thunderstorms will develop ahead
of an approaching cold front Saturday afternoon, with the best
chance of rain likely confined to areas west of the Allegheny
Front. Still some disagreement on timing and coverage of storms
on Saturday afternoon and evening, but most locations east of
I-99 should stay dry. Lows Sunday morning will be the warmest
of the upcoming week, in the upper 50s to mid 60s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
The better chance for thunderstorms will come on Sunday as the
cold front continues to move through the region underneath a
moderately strong upper trough. There appears to be at least
some potential for severe weather with this activity, as most
guidance shows CAPE exceeding 1000 J/kg with 0-6 km bulk shear
in the 25 to 30 knot range. Only a general thunder designation
by SPC at this point, but would not be surprised to see a narrow
Marginal risk drawn along the spine of the Alleghenies in future
updates.

In the wake of the cold front, cooler temperatures are expected
for the first half of next week as upper troughing sets up over
the region. High temperatures will be as much as 5 to 10
degrees below normal Monday through Wednesday, and low
temperatures may drop to near 40 degrees across northwest PA.
The other thing to watch for in this period will be the
potential for lake effect rain showers as 850 mb temperatures
fall to around 5 degrees C. With lake temperatures currently
around 25 degrees C, this is more than enough of a temperature
difference to support lake effect rain showers and associated
cloud cover.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Tonight, widespread VFR conditions should be anticipated across
most TAF sites. Given mainly clear skies and light winds some
valley fog is possible over the northern tier of the state. BFD
is the only site where a mention of fog has been included.
Confidence in fog development is not as high across the rest of
the sites, and no other mention of fog has been made for the
overnight period. Currently satellite is showing any lingering
clouds are quickly dissipating due to the dryer air.

Sat looks like another day of VFR, but more cloud cover is
expected, especially in the western highlands as the dewpoints
rise again. At this point, it looks like we`ll have up to 30%
coverage of SHRA in the afternoon. Prob 30 groups have been
included to cover the possibilities for the afternoon showers on
Saturday. As a front nears from the WNW Sat night we`ll see an
increase in clouds and SHRA/TSRA on Sunday.

Outlook...

Sun...CFROPA. TSRA likely.

Mon-Wed...SCT SHRA/MVFR for BFD. VFR elsewhere.

&&

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

&&

$$

SYNOPSIS...Banghoff
NEAR TERM...Banghoff/Bowen
SHORT TERM...Lambert/Banghoff
LONG TERM...Lambert/Banghoff
AVIATION...Bowen