Storm Prediction Center Mesoscale Discussion 873

   Mesoscale Discussion 0873
   NWS Storm Prediction Center Norman OK
   0406 AM CDT Wed May 27 2026

   Areas affected...Portions of South Texas

   Concerning...Severe Thunderstorm Watch 245...

   Valid 270906Z - 271100Z

   The severe weather threat for Severe Thunderstorm Watch 245
   continues.

   SUMMARY...The risk of large hail and severe wind gusts continues
   with a cluster of storms over South Texas -- within Severe
   Thunderstorm Watch 245.

   DISCUSSION...A cluster of thunderstorms is evolving along the
   east/west-oriented portion of an outflow boundary extending across
   South TX. Here, steep midlevel lapse rates (around 7.5 C/km per
   earlier 00Z observed soundings) atop rich boundary-layer moisture
   (middle/upper 60s to lower 70s dewpoints) are contributing to
   moderate instability -- even immediately north of the outflow
   boundary. This instability and around 40 kt of effective shear will
   continue to promote loosely organized convective clusters capable of
   producing large hail and severe wind gusts. A gust of 58 mph was
   recently measured in Laredo TX at 0841 UTC. Given recent radar
   trends and cold pool evolution with respect to the
   west-southwesterly deep-layer shear, there is some potential that a
   forward-propagating cluster of storms tracks east-southeastward
   along the outflow boundary. This evolution would increase the risk
   of severe wind gusts.

   ..Weinman.. 05/27/2026

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

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

   LAT...LON   27339836 26989856 26819902 26889952 27519963 27789982
               28029969 28189935 28239894 28109855 27829826 27339836 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN