Storm Prediction Center Mesoscale Discussion 1109

   Mesoscale Discussion 1109
   NWS Storm Prediction Center Norman OK
   0348 PM CDT Fri Jun 12 2026

   Areas affected...West Virginia...Virginia...Maryland

   Concerning...Severe Thunderstorm Watch 321...

   Valid 122048Z - 122245Z

   The severe weather threat for Severe Thunderstorm Watch 321
   continues.

   SUMMARY...Storms producing locally damaging gusts may increase in
   coverage over the next several hours with continued wind potential
   over much of Virginia and parts of Maryland.

   DISCUSSION...Two primary areas of thunderstorms have developed this
   afternoon. One is over northern VA within the surface trough, and
   another extends from southeast WV into northeast TN related to the
   residual pre-frontal outflow boundary.

   Substantial moisture and instability have developed into the region
   with daytime heating. Not only are low-level lapse rates steep, but
   GPS PWAT sensors over northern VA have shown a gradual increase in
   moisture as well. The RLX 18Z sounding as well as LWX and RLX VWPs
   show mean midlevel westerlies of 20-30 kt, which supports
   southeastward-moving clusters of storms. The warm and uncapped air
   mass along with ample PWAT and favorable surface lapse rates will
   support corridors of strong to severe gusts through early evening.

   ..Jewell.. 06/12/2026

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

   ATTN...WFO...AKQ...LWX...RNK...PBZ...RLX...

   LAT...LON   37587626 37267708 36587816 36758066 36838152 37138169
               37308142 37828085 38428019 39297928 39387884 39237785
               39037703 38817668 38337603 37587626 

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