Storm Prediction Center Mesoscale Discussion 819

   Mesoscale Discussion 0819
   NWS Storm Prediction Center Norman OK
   0546 PM CDT Thu May 21 2026

   Areas affected...parts of southeastern Colorado...southwestern
   Kansas...and the Oklahoma/Texas Panhandles

   Concerning...Severe Thunderstorm Watch 238...

   Valid 212246Z - 220045Z

   The severe weather threat for Severe Thunderstorm Watch 238
   continues.

   SUMMARY...The evolving thunderstorm cluster may organize further
   with increasing potential to produce strong to severe gusts, in
   addition to severe hail, through 7-8 PM CDT.

   DISCUSSION...Latest Rapid Refresh suggests that upscale convective
   growth the past few hours has been aided by focused lift driven by
   near-surface convergence within lee surface troughing and
   lower/mid-tropospheric warm advection.  The evolving cluster now
   appears to be processing inflow of moistening boundary-layer air
   characterized by CAPE on the order of 1000-2000 J/kg in the peak
   late afternoon heating.  In the presence of strong deep-layer
   westerly shear, further intensification and organization of
   convection appears probable through 23-01Z.  

   Due to the pronounced veering of winds with height, southwesterly
   deep-layer ambient mean flow is only on the order of 20 kt, so
   eastward propagation may be modest, at least until the evolution of
   a strengthening cold pool supports possible acceleration this
   evening.

   ..Kerr.. 05/21/2026

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

   ATTN...WFO...DDC...GLD...AMA...PUB...

   LAT...LON   38120234 38460169 38110099 37070141 36200213 36120299
               36750250 37540226 38120234 

   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