Mesoscale Discussion 2198

 

Mesoscale Discussion 2198
   NWS Storm Prediction Center Norman OK
   1009 AM CDT Wed Sep 02 2026

   Areas affected...Southern Pennsylvania and Maryland

   Concerning...Severe Thunderstorm Watch 642...

   Valid 021509Z - 021615Z

   The severe weather threat for Severe Thunderstorm Watch 642
   continues.

   SUMMARY...An organized storm cluster in Pennsylvania could persist
   into Maryland as the low levels warm, and a downstream watch will
   likely be needed before 16z.

   DISCUSSION...A bowing MCS with ~50 kt rear inflow jet is moving
   southeastward from central PA and will approach the MD border by
   about 16z.  Visible satellite imagery and surface observations
   suggest strong surface heating is ongoing to the south of the MCS
   cloud shield, roughly along and south of a northwest-southeast
   oriented baroclinic zone that extends across the northern Chesapeake
   Bay area.  The phasing of the MCS with the diurnal heating cycle
   suggests the potential for the storms to be maintained into at least
   early afternoon into MD as destabilization continues, and a new
   severe thunderstorm watch will likely be needed in the next hour.

   ..Thompson.. 09/02/2026

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

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

   LAT...LON   40507711 40157669 39607606 39057588 38777605 38687651
               38897722 39427791 39667815 40007842 40297828 40307763
               40507711 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN