Storm Prediction Center Mesoscale Discussion 838

   Mesoscale Discussion 0838
   NWS Storm Prediction Center Norman OK
   0132 PM CDT Sat May 17 2025

   Areas affected...2central to southern Texas

   Concerning...Severe potential...Watch possible 

   Valid 171832Z - 172030Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Thunderstorm development appears likely based on recent
   satellite trends, and will develop in an environment very conducive
   for severe convection. Watch issuance is probable as thunderstorm
   coverage/intensity begins to increase.

   DISCUSSION...Latest GOES visible imagery shows steadily growing
   congestus along a confluence axis/differential heating boundary
   draped from central TX to the Rio Grande and on the northern slopes
   of the Sierra Del Carmen range in northern Mexico. Ahead of the
   building cumulus field, high-quality moisture (dewpoints in the mid
   70s) and temperatures warming into the low to mid 90s are supporting
   MLCAPE values upwards of 3000 J/kg. Despite weak low-level winds,
   increasing mid-level flow ahead of an approaching speed max is
   supporting effective shear values on the order of 45 to 55 knots.
   This convective environment is very favorable for organized
   supercells and may support severe gusts and hail as large as 2 to 3
   inches in diameter. Weak forcing for ascent casts some uncertainty
   on storm coverage, but recent high-res guidance continues to suggest
   rapid thunderstorm development is likely between 20-22 UTC both
   along the boundary and off the northern Mexico mountains. Convective
   trends will continue to be monitored and watch issuance is probable
   as deep convection begin to develop.

   ..Moore/Hart.. 05/17/2025

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

   ATTN...WFO...FWD...EWX...SJT...

   LAT...LON   29710143 31070032 31749947 31909895 31789848 31509813
               31159803 30839807 30579821 30469832 30189866 29069998
               28870030 28760048 28900066 29120076 29340098 29450116
               29540133 29630148 29710143 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN