Mesoscale Discussion 0792
   NWS Storm Prediction Center Norman OK
   0732 AM CDT Wed Jun 03 2020

   Areas affected...Portions of PA

   Concerning...Severe potential...Watch possible 

   Valid 031232Z - 031430Z

   Probability of Watch Issuance...60 percent

   SUMMARY...The severe threat should gradually increase through the
   morning as storms move eastward across Pennsylvania. Damaging winds
   should be the main threat, but isolated large hail may also occur.
   Watch issuance is possible.

   DISCUSSION...Additional storms have recently strengthened this
   morning across northwestern PA along a pre-frontal trough as
   pronounced large-scale ascent associated with a 50-60+ kt mid-level
   jet overspreads this region. As of 1230Z, there is a general lack of
   surface-based instability downstream of this ongoing activity. As
   surface temperatures continue to warm into the 70s and perhaps lower
   80s over the next couple of hours, instability is likewise expected
   to increase, with MLCAPE of 500-1000 J/kg becoming more probable by
   mid to late morning. West-northwesterly flow strengthens quickly to
   50-60+ kt through mid levels based on the 12Z PIT sounding and
   recent VWPs from KCLE and KBUF. 40-50+ kt of effective bulk shear
   will prove more than sufficient for storm organization. At some
   point, ongoing mainly elevated storms will probably become surface
   based, posing an increasing threat for damaging winds. Isolated
   large hail may also occur with any supercells. It remains unclear
   when the severe threat will increase enough to warrant a watch, but
   observational trends are being closely monitored.

   ..Gleason/Guyer.. 06/03/2020

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

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

   LAT...LON   40507956 40868047 41338047 41417987 41897921 41947835
               41957691 41647594 41087566 40117592 39787686 39887811
               40507956