Mesoscale Discussion 0797
   NWS Storm Prediction Center Norman OK
   1122 PM CDT Fri May 28 2021

   Areas affected...Parts of the Texas South Plains into southwestern
   Texas

   Concerning...Severe Thunderstorm Watch 220...222...

   Valid 290422Z - 290615Z

   The severe weather threat for Severe Thunderstorm Watch 220, 222
   continues.

   SUMMARY...It is not certain a new severe weather watch will be
   issued at current Midnight watch expiration, but trends are being
   monitored for this possibility.  At least isolated strong to severe
   storm development may persist into the overnight hours, mainly near
   the Pecos River into the higher terrain to the southwest.

   DISCUSSION...The south-southeastward propagating convective system
   has undergone substantive weakening across parts of the Texas South
   Plains, as low-level inflow has generally become progressively less
   unstable.  However, 55-65+ kt inbound velocities have been evident
   in the lowest 1-2 km on Midland radar, associated with convective
   outflow tending to surge out ahead of the weakening convective line.
    This should begin to weaken across and southeast of the Midland
   area as convection continues to weaken.  However, upslope flow into
   the higher terrain across and southwest of the Pecos River could
   maintain or support additional vigorous thunderstorm development
   through 06-07Z. This is where steep lapse rates associated with
   capping elevated mixed-layer air continues to support large CAPE. 
   In the presence of strong shear (largely due to pronounced veering
   of lower to mid tropospheric wind fields with height), isolated to
   widely scattered supercell development remains possible, posing a
   risk for large hail and locally damaging wind gusts.

   ..Kerr.. 05/29/2021

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

   ATTN...WFO...SJT...MAF...

   LAT...LON   31710410 31950284 31680197 30860161 30860177 30250189
               30450287 30680313 31190377 31710410