Mesoscale Discussion 1570
   NWS Storm Prediction Center Norman OK
   0210 PM CDT Tue Aug 25 2020

   Areas affected...NJ...DE...MD...Northern VA...WV

   Concerning...Severe potential...Watch likely 

   Valid 251910Z - 252045Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Thunderstorms are expected to move into the region with in
   the next hour or two, with an attendant threat for damaging wind
   gusts across a large area from WV into NJ.

   DISCUSSION...Thunderstorms continue to increase in coverage and
   strength upstream of the region over the mid/upper OH Valley.
   Current storm motion estimates bring these storms to the edge of
   Severe Thunderstorm Watch 449 around 2000/2030Z. Air mass from the
   central Appalachians into the northern Mid-Atlantic has warmed in
   the upper 80s/low 90s, removing all convective inhibition and
   resulting in moderate buoyancy. Most recent mesoanalysis estimates
   MLCAPE is near 1000 J/kg and effective bulk shear is around 25-30 kt
   over much of this area. Additionally, robust diurnal heating has
   resulted in steep low-level lapse rates. These steep low-level lapse
   rates coupled with modest mid-level moisture results in an
   environment favorable for strong, water-loaded downbursts.

   As a result, the expectation is for the ongoing storms to move into
   the region within the next hour or two, with an attendant threat for
   damaging wind gusts across a large area from WV into NJ.

   ..Mosier/Bunting.. 08/25/2020

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

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

   LAT...LON   38558270 39467898 40237602 41027447 38927426 37448166
               38558270