849
FXUS61 KCTP 220322
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1122 PM EDT Thu Aug 21 2025

.SYNOPSIS...
* A warming trend Friday into the weekend.
* Gradual clearing Friday as Hurricane Erin tracks northeast,
  several hundred miles east of the coastline.
* Strong thunderstorm potential Sunday followed by a refreshing
  taste of Fall into the last week of August.

&&

.NEAR TERM /THROUGH FRIDAY/...
Early evening update.

A bit of clearing so far, but rather strong inversion will make
for slow improvement before the sun comes up on Friday.

Some valley fog possible late tonight, but slow clearing will
likely limit fog.

Earlier discussion below.

As Erin begins to pull away from the coast, high pressure will
build in and will allow for a clearing and drying trend to
develop tonight. As skies clear out, valley fog will likely
form, with the greatest signal for fog north and west of State
College. Temps will fall into the upper 40s across the northern
tier while areas farther to the south will see low temperatures
in the mid to upper 50s.

&&

.SHORT TERM /FRIDAY NIGHT/...
Early evening update.

Friday could be rather cloudy to start, but still expect
improvement during the day. Still expect a much warmer day.

Earlier discussion below.

Mainly clear skies are expected on Friday as high pressure
builds in at the surface and aloft. Temperatures will be
noticeably warmer, with highs in the upper 70s and low 80s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Early evening update.

While temperatures will likely cool to below normal after
Monday, still think the large scale pattern might favor being
not quite as cool as one expects, but also a bit wetter than
what we might expect.

Earlier discussion below.

The warming trend continues into the first half of the weekend,
with highs on Saturday expected to be around 5 degrees above
normal. Thunderstorms will develop along an approaching cold
front Saturday afternoon, with the best chance of rain likely
confined to areas west of the Allegheny Front. The better chance
for thunderstorms will come on Sunday as the cold front
continues to move through the region. 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.

Much 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.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
High pressure building in overnight will lead to clearing
skies, which should allow for efficient radiational cooling.
Valley fog formation is expected, with BFD, UNV, and AOO
appearing most likely to see visibility restrictions. Fog will
dissipate by 14Z and will give way to VFR conditions with mainly
clear skies and light winds.

Outlook...

Sat...VFR. AM fog possible. Isolated SHRA/TSRA possible

Sun...T-storms likely.

Mon-Tue...Sct rain showers/lower cigs downwind of Lake Erie.

&&

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

&&

$$

SYNOPSIS...Lambert/Martin/Bauco
NEAR TERM...Martin/Bauco
SHORT TERM...Martin/Bauco
LONG TERM...Martin/Bauco
AVIATION...Gartner/Bauco