Mesoscale Discussion 1721
   NWS Storm Prediction Center Norman OK
   0942 PM CDT Wed Sep 08 2021

   Areas affected...Northern Middle Atlantic

   Concerning...Severe Thunderstorm Watch 491...492...

   Valid 090242Z - 090445Z

   The severe weather threat for Severe Thunderstorm Watch 491, 492
   continues.

   SUMMARY...Damaging winds are possible with squall line over the next
   couple hours.

   DISCUSSION...Well-defined squall line has matured and currently
   extends from northern NJ-eastern PA-western MD-northern VA. Over the
   last hour or so, a substantial north-south line segment evolved over
   southern PA and this line has advanced into Berks County PA, with
   some noted acceleration in the last half hour promoting a more
   bow-shaped structure. It appears the greatest short-term wind threat
   will be ahead of this convection as it advances across Berks County
   toward northwestern NJ.

   ..Darrow.. 09/09/2021

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

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

   LAT...LON   38967802 39777677 40597601 41227424 40757408 40007517
               38837709 38967802