Mesoscale Precipitation Discussion 1272
NWS Weather Prediction Center College Park MD
354 AM EDT Sun Sep 13 2026

Areas affected...portions of PA

Concerning...Heavy rainfall...Flash flooding possible

Valid 130753Z - 131053Z

Summary...A broadening area of heavy rain is developing near a
zone of surface convergence.  Hourly rainfall to 2.5" could lead
to flash flooding.

Discussion...A band of thunderstorms is beginning to lengthen not
far from State College PA near a zone of surface convergence/a
weak surface low and within an area of 850 hPa confluence.  MU
CAPE is ~500 J/kg, and rising.  Precipitable water values are
1.75-2".  Effective bulk shear is close to 25 kts.

The guidance had some signal for heavy rain in this area.  This
heavy rainfall should shift east with time along with the 850 hPa
confluence zone.  Hourly rain amounts up to 2.5" are possible
within any training convective bands.  This degree of heavy
rainfall could lead to flash flooding. 

Roth

ATTN...WFO...BGM...CTP...PBZ...

ATTN...RFC...RHA...TIR...NWC...

LAT...LON   42027589 41277606 40237739 39837894 40417939
            41167890 41837747