Mesoscale Discussion 1957
   NWS Storm Prediction Center Norman OK
   0208 PM CDT Wed Sep 11 2019

   Areas affected...Far eastern Ohio...western/central
   Pennsylvania...Portions of Mid-Atlantic

   Concerning...Severe potential...Watch unlikely 

   Valid 111908Z - 112115Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated wind damage from water-loaded downbursts possible
   this afternoon. No WW is planned.

   DISCUSSION...Strong daytime heating of very moist airmass has lead
   to the development of a few clusters of storms in eastern Ohio and
   along the Blue Ridge. So far, convection has remained generally
   shallow; however, storm intensity will likely increase as
   temperatures across the region warm into the upper-80s and low-90s
   F. Deep-layer flow is uniformly weak meaning storms will be only
   loosely organized. The main threat from this activity will be wind
   damage from localized, water-loaded downdrafts as low-level lapse
   rates are quite steep. Any more organized threat from this activity
   would be conditional on cold pools merging and propagating eastward.
   Without upper-level support, this activity should wane at sunset and
   will not likely reach the coast given the stable marine layer
   pushing inland. No WW is planned.

   ..Wendt/Hart.. 09/11/2019

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...PHI...AKQ...BUF...CTP...LWX...RNK...PBZ...RLX...
   CLE...

   LAT...LON   40868144 41438119 42047995 41887810 41507719 40237636
               39067628 38327656 37817692 37717737 37507793 37347868
               37337932 37337985 37848020 38538011 39278020 39938058
               40358111 40868144