Storm Prediction Center Mesoscale Discussion 814

   Mesoscale Discussion 0814
   NWS Storm Prediction Center Norman OK
   1159 AM CDT Fri May 16 2025

   Areas affected...the Cumberland Plateau and southern Appalachians

   Concerning...Severe Thunderstorm Watch 261...

   Valid 161659Z - 161900Z

   The severe weather threat for Severe Thunderstorm Watch 261
   continues.

   SUMMARY...Severe wind-driven large hail will be possible, amid
   several supercells that will likely move east across parts of the
   Cumberland Plateau and southern Appalachians.

   DISCUSSION...A string of several supercells have evolved out of an
   earlier MCS, amid very strong deep-layer speed shear per area VWP
   data. The strongest supercell across Floyd to Pike counties in KY
   has had a wind-driven hail signature with its small-scale bowing
   structure and more pronounced MRMS MESH core. Upstream supercells,
   trailing to its west-southwest, may undergo a similar evolution
   given the ample buoyancy and greater than 60 kts of effective bulk
   shear. The 15Z HRRR appears to have a poor handle on downstream
   evolution of this activity given the established supercell
   structures heading into peak heating. Expectation is for a mix of
   wind/hail swaths to likely persist east and spread into southwest
   VA, as well as adjacent portions of TN/NC/WV. Tornado threat appears
   to be still limited by weak 0-1 km shear/SRH.

   ..Grams.. 05/16/2025

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

   ATTN...WFO...RNK...RLX...MRX...JKL...

   LAT...LON   37628270 37868085 37718006 37397985 37067989 36458025
               36318131 36448389 36528462 37348432 37628270 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN