Mesoscale Discussion 0294
   NWS Storm Prediction Center Norman OK
   0157 PM CDT Tue Apr 07 2020

   Areas affected...Northeast West Virginia...northern Virignia and
   portions of Maryland

   Concerning...Severe potential...Watch possible 

   Valid 071857Z - 072030Z

   Probability of Watch Issuance...40 percent

   SUMMARY...The threat for severe hail and wind is expected to
   increase after 20Z across parts of the Mid Atlantic.

   DISCUSSION...Recent satellite imagery shows increasingly agitated
   cumulus along and ahead of a remnant outflow boundary across eastern
   WV and in the vicinity of an embedded vorticity maxima located in
   northern WV. These features are co-located with a region of modest
   warm air advection rooted between 925-850 mb. Combined, these
   features will act as the impetus for convective initiation across
   northeast WV and northern VA in the coming 1-3 hours. 

   Although this environment will likely feature modest instability
   between 500-750 J/kg MLCAPE, 45-50 knots of effective bulk wind
   shear and sustained forcing for ascent may be able to compensate for
   the instability and will support a hail threat with any stronger
   storms. Additionally, steep boundary layer lapse rates on the order
   of 7-8 C/km already in place across the region (per SPC
   Mesoanalysis) suggests the potential for strong, downdraft-driven
   winds. Due to these considerations, a watch may be needed if
   confidence increases that sustained organized convection will occur.

   ..Moore/Hart.. 04/07/2020

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

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

   LAT...LON   37787832 38007919 38297981 38608019 38888021 39287998
               39557957 39327846 38877706 38577602 38317537 38057529
               37737543 37307564 37217608 37327666 37787832