Storm Prediction Center Mesoscale Discussion 877

   Mesoscale Discussion 0877
   NWS Storm Prediction Center Norman OK
   1250 PM CDT Mon May 19 2025

   Areas affected...Eastern Kansas into far eastern Missouri

   Concerning...Severe potential...Watch likely 

   Valid 191750Z - 191945Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Thunderstorm development along and ahead of the dryline is
   anticipated by mid-afternoon across eastern Kansas. Thunderstorms
   will quickly become severe given a very unstable and strongly
   sheared environment as they spread east into Missouri. Additional
   thunderstorms moving out of northeast Oklahoma will pose a severe
   threat for southwest Missouri in the coming hours. Watch issuance is
   likely.

   DISCUSSION...GOES imagery shows slowly clearing skies and the
   gradual decay of stable waves across eastern KS, indicating steady
   erosion of MLCIN that was sampled in the 12 UTC TOP sounding.
   Modifying this sounding based on current temperatures/dewpoints
   within the clearing warm sector suggests only around -50 J/kg MLCIN
   remains, with further reduction expected as daytime heating
   continues and large-scale ascent overspreads the region with the
   arrival of the upper-level trough from the west. Recent HRRR
   solutions hint that thunderstorm development along and ahead of the
   dryline is likely between 19-21 UTC, but temperatures are currently
   a few degrees warmer than what guidance depicts, suggesting an
   earlier initiation time is possible. Highly unstable conditions
   (MLCAPE over 3000 J/kg) and strong deep-layer shear associated with
   the mid-level jet streak (0-6 km shear on the order of 50-60 knots)
   will promote rapid storm intensification and organization into
   supercells with all hazards possible, including very large hail (2-3
   inches in diameter), and potentially strong tornadoes. 

   Additionally, strong/severe thunderstorms ongoing across eastern OK
   are expected to spread northeast into southwest MO by mid-afternoon.
   A favorable convective environment already in place across western
   MO will maintain the severe threat. Watch issuance is expected as
   soon as thunderstorm development is imminent and/or as convection
   approaches the northeast edge of WW 292.

   ..Moore/Hart.. 05/19/2025

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

   ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT...OUN...

   LAT...LON   37089714 37379723 39739714 39939708 40069683 40139525
               40099496 39969473 39739457 37649375 37309370 36949386
               36839417 36909469 36959687 37089714 

   MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
   MOST PROBABLE PEAK WIND GUST...75-90 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN