Storm Prediction Center Mesoscale Discussion 812

   Mesoscale Discussion 0812
   NWS Storm Prediction Center Norman OK
   0514 AM CDT Fri May 17 2024

   Areas affected...South Texas

   Concerning...Severe potential...Watch unlikely 

   Valid 171014Z - 171215Z

   Probability of Watch Issuance...20 percent

   SUMMARY...A cluster of thunderstorms -- including a couple of
   stronger/rotating updrafts -- continues to evolve over South Texas. 
   Isolated instances of large hail can be expected, but isolated
   nature of the risk should mitigate the need for WW issuance.

   DISCUSSION...Latest radar loop shows clusters of storms moving
   into/developing across portions of South Texas over the past couple
   of hours, where ample instability is indicated atop a surface-based
   stable layer.  The development appears to be a result of weak warm
   advection north of a cold front, which has now pushed south to the
   lower Rio Grande Valley.

   Strong mid-level southwesterly flow is contributing to ample
   cloud-layer shear for updraft rotation within a few of the more
   vigorous storms, and associated indications of hail exceeding severe
   levels from time to time.  Expect this trend to continue over the
   next few hours, though with the overall coverage of the hail risk
   currently expected to remain isolated enough so as to preclude the
   need for WW issuance.

   ..Goss/Edwards.. 05/17/2024

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

   ATTN...WFO...HGX...CRP...EWX...BRO...

   LAT...LON   28070018 28609989 29109813 29229688 27949712 26939789
               26629938 26999971 28070018