Mesoscale Discussion 0339
   NWS Storm Prediction Center Norman OK
   0751 PM CDT Sat Apr 11 2020

   Areas affected...The Edwards Plateau area of Texas and adjacent Rio
   Grande Valley

   Concerning...Severe potential...Watch possible 

   Valid 120051Z - 120215Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Severe risk is forecast to increase with time across the
   Edwards Plateau and vicinity.  Large hail should be the main risk,
   though potential for locally damaging winds a possibly a tornado or
   two will also exist.

   DISCUSSION...Latest radar loop shows a persistent storm just to the
   Mexican side of the Rio Grande west of Del Rio, which has
   intensified over the past half hour.  High-res CAM output continues
   to suggest that an isolated storm or two may cross the River into
   the Val Verde/Edwards/Kinney County vicinity this evening,
   consistent with the evolution of this cell.

   Other congested cumulus over the Mexican higher terrain has remained
   steady-state, with some signs of decrease recently, in conjunction
   with diurnal cooling.  However, as ascent with the approaching
   southern AZ upper low continues advancing eastward, a later, more
   widespread increase in storms is expected across southwestern Texas.
    A consistent signal persists in CAM output that rather rapid,
   widespread convective development -- separate from the current storm
   -- will occur, within the 04Z to 06Z time frame.  The expected,
   isolated nature of the current convection may permit delay in WW
   issuance in the short term.  Potential for watch issuance will
   increase later this evening however, as the aforementioned UVV
   spreads eastward toward this region.

   ..Goss/Hart.. 04/12/2020

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

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

   LAT...LON   29470169 30110178 30450141 30570027 30459989 29949951
               29359973 28920054 29470169