Mesoscale Discussion 1823
   NWS Storm Prediction Center Norman OK
   1126 AM CST Mon Nov 30 2020

   Areas affected...Portions of eastern NC/VA...central/eastern
   MD...DE...far southeastern PA...and southern/central NJ

   Concerning...Severe potential...Watch possible 

   Valid 301726Z - 302000Z

   Probability of Watch Issuance...40 percent

   SUMMARY...The threat for storms capable of producing isolated
   damaging wind gusts and a couple tornadoes may increase this
   afternoon. Watch issuance is possible.

   DISCUSSION...At 1725Z, surface observations and recent visible
   satellite imagery indicate some heating has occurred across eastern
   NC/VA into the Delmarva Peninsula and southern NJ ahead of cold
   front, as temperatures have generally warmed into the mid 60s to mid
   70s. Around 500-1000 J/kg of MLCAPE has already developed early this
   afternoon across the warm sector, with locally higher instability
   across the Outer Banks of NC. Around 50-60 kt of south-southwesterly
   winds is being estimated only 1 km AGL from multiple VWPs across
   this region, with even stronger winds noted in mid levels. Both
   low-level and deep-layer shear are more than sufficient for
   organized severe storms including supercells, with recent
   mesoanalysis estimates suggesting upwards of 45-55 kt of effective
   bulk shear present. There will be some potential for robust storms
   to develop along the eastward-moving cold front across eastern NC
   and southeastern VA, and then move quickly northeastward. Other
   storms may develop ahead of the front in a strong low-level warm
   advection regime.

   Given the strength of the low-level flow, isolated severe/damaging
   wind gusts from convective downdrafts may occur even though
   instability should remain fairly weak. A couple of tornadoes also
   appear possible as modest veering but rapid strengthening of the
   low-level wind profile will support large effective SRH values (200+
   m2/s2). The primary uncertainty regarding the severe threat through
   this afternoon is overall convective coverage, as low-level
   convergence along the cold front is not particularly strong given a
   largely unidirectional (southerly) wind profile. Regardless,
   observational trends will be monitored closely for increasing storm
   coverage/intensity and possible watch issuance across some portion
   of this region.

   ..Gleason/Hart.. 11/30/2020

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

   ATTN...WFO...PHI...AKQ...MHX...LWX...RAH...

   LAT...LON   34587649 34727703 34757760 35387849 36147821 37047780
               38997661 39967577 40287542 40347491 40147447 39677409
               39217454 38757498 38367500 37777547 37417567 37067586
               36737589 36397576 36007558 35727542 35327544 35167557
               35047598 34587649