Mesoscale Discussion 1666
   NWS Storm Prediction Center Norman OK
   1119 PM CDT Tue Aug 31 2021

   Areas affected...northern VA into MD

   Concerning...Severe potential...Watch possible 

   Valid 010419Z - 010545Z

   Probability of Watch Issuance...40 percent

   SUMMARY...A couple of strong cells capable of producing brief
   tornadoes may spread northeast across parts of northern Virginia and
   western Maryland.

   DISCUSSION...A few persistent cells across central VA continue to
   show periods of low-level rotation as they track along the gradient
   of stronger 0-3 km MLCAPE. Forecast guidance shows this area of
   relatively greater instability persisting over parts of northern VA
   and MD. Low-level shear currently is weak downstream from WW 480
   across the MCD area. However, some improvement is forecast as
   stronger ascent spreads over the region and the stalled surface
   boundary lifts northward. This could support a few stronger cells
   with a continued tornado threat into the overnight hours, and a
   downstream tornado watch is possible.

   ..Leitman/Edwards.. 09/01/2021

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

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

   LAT...LON   38107736 38247777 38587810 38727809 38917804 39217755
               39257674 39067630 38707626 38357635 38197667 38127701
               38107736