597
FXUS61 KCTP 221106
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
706 AM EDT Fri Aug 22 2025

.SYNOPSIS...
* A warming trend begins today and continues into the weekend.
* Scattered strong thunderstorm potential on Sunday followed by
  a refreshing taste of Fall into the last week of August.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
The prolonged period of moist easterly flow off the Atlantic
that brought overcast and cool conditions to the region will
end today as an extensive ridge of high pressure builds south
into the region.

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 Central and Northern PA through the mid
morning hours.

Abundant sunshine, comfortable humidity with surface dewpoints
in the 50s and near normal temperatures in the upper 70s to low
80s will combine to give us fantastic weather to close out the
workweek.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Clear skies, light wind and cool temps once again tonight under
the ridge of high pressure will lead to areas of early to mid
morning valley fog once again.

Low temps will be similar to this morning`s across the south,
and likely a few deg warmer across the northern half of the
state.

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 Sat afternoon will be similar if not a deg F or so
warmer than today (Friday).

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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 /11Z FRIDAY THROUGH TUESDAY/...
Fog has worked it`s way throughout almost all the valleys of the
CWA N & W of MDT and HGR. Mixing should allow the fog to be
dissipated by 14 at most sites, but a patch of low clouds over
BFD may cause it to linger longer there. SCT cu will develop
over the western highlands, but the clouds will be >3kft/VFR.
The wind will be very light, and if they are any stronger,
they`ll otherwise be out of the N/NE.

There could be additional fog Fri night in the valleys of the
north, but we have 70% certainty that it won`t be at any of the
TAF sites. So, left out any mentions of fog for the latter 6
hrs. Sat looks like another day of VFR, but more cu is
expected, esp in the wrn highlands as the dewpoints rise again.
At this point, it looks like we`ll have up to 30% coverage of
SHRA in the aftn in the west (JST/BFD). They are too far out in
time to make it into this pkg (12Z Fri) TAFs. As a front nears
from the WNW Sat night we`ll see an increase in clouds and
SHRA/TSRA.

Outlook...

Sun...CFROPA. TSRA likely.

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

&&

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

&&

$$

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