Mesoscale Discussion 0729
   NWS Storm Prediction Center Norman OK
   0504 PM CDT Mon May 25 2020

   Areas affected...far south Texas

   Concerning...Severe potential...Watch possible 

   Valid 252204Z - 260000Z

   Probability of Watch Issuance...40 percent

   SUMMARY...A threat for large hail and strong winds is possible with
   storms developing along a stationary front/outflow boundary in far
   south Texas. Uncertainty remains on the initial storm coverage, but
   severe probs will likely increase later this evening. A weather
   watch may be needed.

   DISCUSSION...Afternoon water vapor imagery shows a mid-level
   shortwave trough emerging from the Mexican Plateau over southwest
   Texas. At the surface, a pseudo stationary front/modified outflow
   boundary has penetrated into far south Texas. 21z SPC analysis
   indicates that a warm and moist environment is present south of this
   boundary, with temperatures and dewpoints in the 80s-90s and low to
   mid 70s F respectively. This is supporting moderate to extreme
   instability, with MLCAPE of 2500-4000 J/kg. Mid-level flow ahead of
   the shortwave trough should support 30-40 kt of effective shear.
   Organized multicells and some supercells with the potential for
   large hail and strong winds will be the primary short-term threats. 

   There is considerable uncertainty on the coverage of the initial
   convection across the area this afternoon. Hi-res guidance suggests
   that a more substantial threat for severe weather may develop later
   in the evening ahead of an upscale growing MCS from convection
   developing across northern Mexico. A severe weather watch is
   possible in the short term, but may be more likely in a few hours.

   ..Lyons/Guyer.. 05/25/2020

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

   ATTN...WFO...CRP...BRO...

   LAT...LON   28119993 27789858 27089726 26629700 25849693 25629710
               25789781 26009851 26319913 27869999 28119993