FXUS61 KCTP 090018
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
818 PM EDT Wed Jul 8 2026

.WHAT HAS CHANGED...
* Upgrade to level 2/4 excessive rain and flash flood risk for
  south central and southeast PA Thursday afternoon & evening

&&

.KEY MESSAGES...
1) Torrential downpours and strong to locally damaging 
thunderstorm wind gusts may impact portions of south central PA
Thursday afternoon and evening

&&

.DISCUSSION...
KEY MESSAGE 1: Torrential downpours and strong to locally 
damaging thunderstorm wind gusts may impact portions of south 
central PA Thursday afternoon and evening 

Most CAM guidance indicates a forward-propagating tstm cluster 
moving across southern PA/northern MD and the DelMarVa area
tomorrow afternoon before tracking offshore the Mid-Atlantic 
coast by late evening. SPC upgraded to a level 2/5 SLGT risk
which clips southern York and Lancaster Counties. The remainder
of the Lower Susquehanna Valley is in a level 1/5 MRGL risk 
with potential for strong to perhaps locally damaging wind gusts
dependent/contingent on location of strongest storms. The best 
CAPE and shear overlap is forecast farther to the south over 
the DelMarVa. HREF shows 2+ inch pwats available this area to 
drive very intense rain rates and increased flash flood risk. 
WPC will upgrade the excessive rainfall outlook to level 2/4 for
Thursday in their updated forecast later this afternoon.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
SCT-BKN low clouds will linger through this evening, 
particularly along and east of the Alleghenies where a corridor 
of moisture at 925 mb (RH values around 75-90%) will persist. 
This moisture will trend toward eastern Pennsylvania overnight 
as winds veer aloft over the western 2/3rds of the 
Commonwealth & allow for drier air to filter in. Areas of 
mist/fog will likely develop where low-level clouds clear out 
(KBFD/KJST/KAOO/KUNV), with cloud ceilings expected to develop
and lower to MVFR-IFR where the moisture lingers 
(KIPT/KMDT/KLNS). Furthermore, spotty showers will be possible 
along and north of the PA/NY border (less than PROB30 for 
impacts at KBFD/KIPT at this time), with scattered 
shower/thunderstorm activity along the Mason-Dixon border 
overnight (PROB30s for -SHRA/SHRA at KMDT & KLNS between 
10Z-14Z Thursday).

Gradual improvements to VFR are expected through the morning 
as overnight mist/fog mixes out & low ceilings over eastern 
Pennsylvania lift through the early afternoon. A shortwave 
approaching from the Ohio Valley will spur on more numerous 
showers and thunderstorm activity during the afternoon,
especially over southern/central portions of the state where 
better instability (MLCAPE around 1000-2000 J/kg) and forcing 
ahead of the shortwave overlap. Ample moisture (precipitable 
water values approaching 2") suggests that heavy rain may accompany
this convection, with visibility restrictions to MVFR-IFR 
likely in the stronger showers/storms. Water-laden updrafts and
modest low-level lapse rates (6-7 C/km) may also support locally gusty
winds with these storms.

Outlook...

Fri...T-storm impacts likely during the afternoon. AM low 
clouds and fog possible. 

Sat...Reduced chance and more limited coverage of PM 
showers/t-storm.

Sun-Mon...Mainly VFR/no sig wx.

&&

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

&&

$$

WHAT HAS CHANGED...Steinbugl
KEY MESSAGES...Steinbugl
DISCUSSION...Steinbugl
AVIATION...Teare