Mesoscale Discussion 1601
   NWS Storm Prediction Center Norman OK
   0550 PM CDT Thu Aug 27 2020

   Areas affected...Arkansas into western Tennessee...northern
   Mississippi

   Concerning...Tornado Watch 458...

   Valid 272250Z - 280045Z

   The severe weather threat for Tornado Watch 458 continues.

   SUMMARY...The threat for a few tornadoes persists east through north
   of the center of Laura.

   DISCUSSION...An arcing band of storms containing periodic rotation
   and signs of strong wind gusts continues to move northward across
   central and eastern AR, with a trailing, broken line of storms
   arcing southeast into northwest MS.

   While surface temperatures are only in the lower 80s in many
   locations, dewpoints of 75-77 F are resulting in 1000-1500 J/kg
   MLCAPE, with the most unstable air from northeast AR into TN and KY.

   Surface analysis continues to show strong pressure falls ahead of
   the line of storms, with increasing low-level shear. A recent
   measurement from the Memphis VWP showed 350 m2/s2 0-1 km SRH which
   is quite favorable for tornadoes. Winds continue to gust out of the
   due east across western TN and northeast AR, which should favor
   storm longevity for a few hours as they develop northward.

   In addition, isolated cells ahead of the main line cannot be ruled
   out as forcing for ascent increases. Though small, any cellular
   activity may produce brief tornadoes.

   ..Jewell.. 08/27/2020

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

   ATTN...WFO...MEG...LZK...

   LAT...LON   34109058 34289078 34719130 34869204 34859240 35139279
               35649195 36019083 36098993 35818958 35528947 34748970
               34198991 33939036 34109058