FXUS61 KCTP 090626
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
226 AM EDT Thu Jul 9 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 /06Z THURSDAY THROUGH MONDAY/...

Over the next few hours, visibility restrictions will begin to
intrude on Central PA TAf sites. Highest confidence in these
restrictions are at BFD, JST, AOO, and UNV as skies clear with
dry air filing in over the western 2/3rds of the Commonwealth 
tonight. Restrictions at IPT, MDT, and MDT later tonight and 
into the morning are more likely in the form of ceiling 
lowerings. These are most likely in the form of MVFR 
restrictions although may boarder on IFR at MDT and LNS as more 
moisture gets pumped in from the south.

As the sun comes out tomorrow, this will mix out widespread
restrictive mist/fog and low cloud ceilings. Restrictions are
likely to return in the form of numerous showers and
thunderstorms as a shortwave trough moves in from the Ohio River
Valley. Greatest coverage of storms is likely in the southern
tier of the state, particularly at MDT and LNS in the 
afternoon. With tall CAPE profiles, minimal capping, and PWATs 
approaching 2", repeating, scattered, heavy showers and 
thunderstorms are possible, leading to visibility restrictions 
as they pass. Isolated instances of gusty winds may also 
accompany these storms. 

In the wake of this convective activity, the moist low levels 
may lead to mist/fog developing over Southeast PA. At this 
time, the best chances for these restrictions from this fog/mist 
appear to be after 06Z so may introduce mentions in future TAF
packages. 


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...Lambrech