432
FXUS61 KCTP 191919
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
319 PM EDT Tue Aug 19 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 WEDNESDAY MORNING/...
SE llvl flow keeping the clouds thicker over the s-central mtns,
but holes continue to appear as mixing works the moisture in
with the drier air aloft and near sfc. Radar at 19Z shows
returns getting into PA from LE, but most of the returns are
aloft thus far. While there could be --SHRA for Warren Co before
dark, we will leave the PoPs and QPF nil until sunset
considering the drier air over the NWrn part of the CWA.
SHRA/TSRA will move in from the NW, but likely not get into the
Lower Susq by morning. The low clouds should re-establish
themselves tonight, and may lead to a patch or two of DZ, but
likely not enough to paint in the grids. Cold front gets to the
OH/PA border by sunrise. But, we`ll be more in a cool airmass
vs a true warm sector.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
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 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 /19Z TUESDAY THROUGH SUNDAY/...
Mix of low VFR and MVFR cigs expected into the evening. Cigs
will lower to MVFR/IFR/LIFR overnight into Wednesday morning.
Showers are most likely to track across the northern airspace
late tonight into Wednesday morning with a few thunderstorms
possible across the southern airspace Wednesday afternoon. Sub-
VFR cigs are probable Wednesday night through Thursday morning
with slow/gradual improvement through Thursday night.

Outlook...

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

Sun...T-storms likely.

&&

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

&&

$$

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