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Area Forecast Discussion (AFD)

Issued by State College, PA (CTP)

FXUS61 KCTP 201739

Area Forecast Discussion
National Weather Service State College PA
139 PM EDT Tue Aug 20 2019


It will remain very warm and humid through Wednesday. A warm 
front lifting north across the state today will provide the
focus scattered, mainly afternoon showers and thunderstorms. 
A pair of cold fronts will push southeast through the state late
Wednesday into early Thursday bringing cooler and much less 
humid air will that will last into the weekend.



Radar showing convection starting to fire over the Laurel 
highlands within an area of weak low level convergence. RAP 
shows CAPE in the 1000-15000J range, but deep layer shear is 
very weak, arguing against significant storm organization 
potential. The storms are right on the gradient between 
respectable Downdraft Cape and very DD Cape. 

Over the remainder of the area, the beat goes on with another
day of very warm and humid conditions in place. There seems to 
be very little focus to organize the convection, and the various
flavors of the HREF show the convection remaining scattered and
disorganized into the overnight.

Overall we expect mainly garden variety storms, but cannot rule
out an isolated damaging wind gust/large hail with some of the
more robust updrafts.

Max temps this afternoon will range from the low-mid 80s across
the northern and western mountain, to the L90s in the SE metro 

Yet another warm/muggy night is on tap for tonight with partly
cloudy skies and isolated to scattered showers roaming the

Min temps will be in the around 70F in the SE.



Wednesday will see slightly higher probability for active 
convection, mainly during the afternoon and evening as a more 
vigorous upper shortwave and associated cold front pushes 
southeast through the CWA late in the day and evening.

SPC has a broader MRGL Risk covering the majority of our CWA on
Wednesday, at the SW edge of a fairly large SLGT Risk area 
across upstate NY and WRN New England.



Secondary SFC cfront and CFA dropping SE from the Glakes 
Thursday should trigger a few afternoon showers/TSRA across 
mainly the SE half of PA. 700 mb temps will likely cool off by
at least 2-3C during the day Thursday.

Look for refreshingly cooler max temps Thursday ranging from the
low to mid 70s over the Northern Mtns to the L-M 80s in the Susq
Rain risk will linger across south central PA on Friday as the
frontal boundary continues to sink southward into the southern
Mid Atlantic. 

A sprawling area of Canadian high pressure should bring a
multi-day stretch of fair weather to central PA Saturday to
Monday. Temperatures will be near average with pleasant and 
warm afternoons and comfortably cool nights.



Widespread VFR will continue into the evening, with only brief
restrictions this afternoon at terminals affected by the roaming
showers and thunderstorms.

Areas of low clouds and fog will form once again overnight,
before burning off within a couple of hours of sunrise Wed.

Showers and thunderstorms will once again boil up for Wednesday
afternoon and evening associated with a cold front. They will 
have the potential to bring brief restrictions, gusty winds and 


Thu...PM thunderstorms southeast 1/2.

Fri...Chance of showers southern 1/4. 

Sat-Sun...AM fog possible.




NEAR TERM...La Corte
LONG TERM...Steinbugl