Mesoscale Discussion 0578
   NWS Storm Prediction Center Norman OK
   0520 PM CDT Wed May 13 2020

   Areas affected...southwest Texas

   Concerning...Severe Thunderstorm Watch 180...

   Valid 132220Z - 132315Z

   The severe weather threat for Severe Thunderstorm Watch 180
   continues.

   SUMMARY...Large hail and strong winds remain a hazard with
   thunderstorms across WW 180. Recent trends suggest a lack of
   organization due to weak deep-layer shear. Congealing outflow may
   allow storms to move farther east into better low-level moisture and
   intensify, but the evolution of these storms is uncertain at this
   time.

   DISCUSSION...Storms across the western portion of WW 180 have
   struggled to maintain organized structures over the last hour. These
   storms are ongoing in the immediate vicinity of a diffuse dryline,
   in a relative minima of mid-level flow. While thermodynamics are
   supportive of severe weather with SPC mesoanalysis indicating MLCAPE
   of 1500-2000 J/kg, bulk shear from the MAF VWP is weak, at or below
   25 kt. The weak mid-level flow has kept storms close to the dryline
   and relatively disorganized. Competing updrafts and downdrafts have
   limited the intensity to marginally severe for now. Conglomerating
   outflow may eventually push storms farther southeast into higher
   MLCAPE around 3500 J/kg, and marginally better deep-layer shear.
   Here, storms would pose a more substantial damaging wind threat.
   However, recent hi-res guidance has suggested this is not certain.
   Meanwhile, the greatest severe threat corridor will likely remain
   close to the dryline southwest of MAF.

   ..Lyons/Hart.. 05/13/2020

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

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

   LAT...LON   29480305 29510330 29610329 30170340 31060330 31800315
               32290290 32510266 32660231 32720159 32740105 32770078
               32470048 32000041 31620041 31210045 30690059 30120086
               29800087 29480092 29400094 29440103 29790148 29840210
               29810267 29670290 29480305