Storm Prediction Center Mesoscale Discussion 862

   Mesoscale Discussion 0862
   NWS Storm Prediction Center Norman OK
   0511 PM CDT Sun May 18 2025

   Areas affected...Parts of northwestern Oklahoma into extreme
   southwest Kansas

   Concerning...Tornado Watch 287...

   Valid 182211Z - 182345Z

   The severe weather threat for Tornado Watch 287 continues.

   SUMMARY...Supercell tornado threat increasing across parts of
   northwestern Oklahoma into extreme southwest Kansas during the next
   couple hours.

   DISCUSSION...Splitting supercells are evolving across the
   northeastern Texas Panhandle. While these storms are gradually
   impinging on the richer boundary-layer moisture (upper 60s
   dewpoints), they are still in the slightly higher-mixed/lower SRH
   air at this time. As a result, splitting-supercell mode may continue
   in the immediate near-term, with an associated risk of very large
   hail and severe wind gusts. With time, these storms will continue
   spreading/developing northeastward into northwest Oklahoma, where
   visible satellite imagery depicts an antecedent sheltered boundary
   layer (with around 300 m2/s2 0-1km SRH per VWP and mesoanalysis
   data) and lower 70s dewpoints becoming increasingly unstable. Given
   the high SRH and strong/extreme surface-based instability here, and
   further increases in clockwise hodograph curvature/helicity into the
   evening with the strengthening low-level jet, the supercell tornado
   risk will continue increasing over the next couple hours. If a
   dominant right-mover can evolve, a strong/intense tornado will be
   possible.

   ..Weinman.. 05/18/2025

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

   ATTN...WFO...OUN...DDC...AMA...

   LAT...LON   35929987 36100008 36430031 36800024 37020001 37069968
               36889924 36499894 36119893 35929907 35859959 35929987 

   MOST PROBABLE PEAK TORNADO INTENSITY...140-170 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN