892
FXUS61 KCTP 200537
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
137 AM EDT Wed Aug 20 2025

.SYNOPSIS...
* Cold front approaches from the west, but stalls briefly over
  western PA before moving through Central PA on Wed.
* High pressure over eastern Canada will help keep Erin offshore
  and PA dry as the hurricane passes our latitude.
* A refreshing taste of Fall likely to arrive into the last
  week of August

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Low clouds are expanding this evening and will gradually lower
through the night. The clouds will likely intersect the higher
terrain of the Laurel Highlands and may reduce visibility to 1/2
mile or less on the ridgetops into the morning. Low
temperatures tonight will range from the upper 60s over the
northern tier to the mid 60s in the Lower Susquehanna Valley.

Showers and a few thunderstorms ahead of an approaching cold
front are beginning to enter northwest PA and will continue to
move in through the rest of the night. The best chance for rain
will likely be confined to far northern Pennsylvania, though
showers may make it as far south as State College by sunrise.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
Flow over PA becomes NErly thru the day and Wed night as the sfc
low inching across PA melts into oblivion, and the giant
circulation around Erin takes over. Forcing is present in the
form of two short wave vort maxes but PWATs are not impressive
at all - unless it is February. So, the worry for heavy rainfall
is low. Still, the possible slow movement of cells Wed could be
a slight (MRGL) cause for excessive rainfall, mainly in the
central zones. Lingering forcing and boundaries for the
overnight keeps SHRA/isold TSRA in the forecast until dry air
moves in from the NE.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Confidence is high for the long range. Large scale subsidence
to the west of departing Hurricane Erin provides a mainly dry
Thurs and all dry Fri. Erin passes well to the east of PA with
max wind only 12KT with gusts under 20KT in Lancaster Co Thurs.
Rising heights into the weekend will promote a warming trend
with highs rebounding back into the lower 80s for Friday and
through the whole weekend.

Longer range model and ensemble data continues to show a more
formidable upper trough digging into the Great Lakes and
amplifying this weekend over the Eastern U.S. Moisture
returning northward from the Gulf along the leading frontal
boundary should provide a focus for showers and storms with max
POPs Sat-Sun as it moves slowly eastward from the Appalachians
toward the Mid Atlantic coast.

Taste of Fall on the horizon for at least the first part of next
week as cooler/more refreshing air filters into the region from
Canada.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Showers over the northern tier of Pennsylvania will bring
continued IFR conditions to BFD over the next couple of hours
with brief rises of MVFR through the near-term. A heavier bath
of rainfall is expected over the next two hours, bringing
locally lower visibilities with rises in visibility overnight at
BFD. All model guidance points to increasingly moist low-levels
overnight, with IFR becoming increasingly likely by 12Z
Wednesday at all airfields across central Pennsylvania.

Low-level cloud deck will remain fairly persistent with
improvements limited to the Susquehanna Valley with brief
increases to MVFR for a two-three hour period during the
afternoon hours. Borderline VFR conditions will be possible;
however, lower condifence across all airfields to promote
inclusion into the TAF under east/southeasterly flow. TSRA
potential will increase across the southeastern airspace
(MDT/LNS) in the 18Z Wednesday-03Z Thursday timeframe; however,
confidence in timing/placement of TSRA remains low, thus there
has been no inclusion in the 06Z TAF package. Sub-VFR cigs are
probable once again after 03Z Wednesday through 06Z Thursday.

Outlook...

Fri-Sat...VFR. AM fog possible.

Sun...T-storms likely.

&&

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

&&

$$

SYNOPSIS...Dangelo
NEAR TERM...Bauco
SHORT TERM...Dangelo
LONG TERM...Dangelo/Steinbugl
AVIATION...NPB