Mesoscale Discussion 1782
   NWS Storm Prediction Center Norman OK
   0930 AM CDT Thu Sep 23 2021

   Areas affected...Portions of the Delmarva Peninsula into
   southeastern PA and NJ

   Concerning...Severe potential...Watch unlikely 

   Valid 231430Z - 231630Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Sporadic strong to damaging wind gusts may continue
   through the early afternoon. Watch issuance remains unlikely.

   DISCUSSION...A north-south oriented band of storms should continue
   to make slow eastward progress across the Delmarva Peninsula over
   the next couple of hours. This activity is occurring along a surface
   cold front, with a moist low-level airmass present to its east. As
   filtered diurnal heating occurs through the remainder of the
   morning, the boundary layer should gradually destabilize, with
   around 500-1000 J/kg of MLCAPE eventually developing. Even so,
   multiple limiting factors remain apparent, including poor mid-level
   lapse rates tempering updraft strength, stronger deep-layer shear
   likely remaining confined to the cool side of the surface front, and
   nearly meridional flow above 1 km AGL limiting opportunity for the
   band of storms to develop eastward more quickly.

   Recent inland observations across eastern MD show that gusty outflow
   winds within the band have remained generally below 40 mph. While
   sporadic strong to damaging wind gusts may still occur as the line
   continues to advance slowly eastward, this threat should remain
   quite isolated/marginal. Finally, there is some low-level shear
   present ahead of the line from far eastern MD into DE and
   southeastern PA/western NJ. Recent VWPs from KDOX and KDIX show
   around 25-30 kt of 0-1 km shear, with about 150-200 m2/s2 of 0-1 km
   SRH also present. Even with the less than favorable orientation of
   the line, an embedded low-level circulation capable of producing a
   brief tornado appears possible. Regardless, the overall severe
   threat is expected to remain rather marginal owing the previously
   mentioned limiting factors, and watch issuance is unlikely at this
   time.

   ..Gleason/Hart.. 09/23/2021

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

   ATTN...WFO...PHI...AKQ...CTP...LWX...

   LAT...LON   38387589 38737592 39577616 40177615 40697590 40967569
               40907512 40167470 39537477 38937497 38557521 38307546
               38387589