Storm Prediction Center Mesoscale Discussion 1252

   Mesoscale Discussion 1252
   NWS Storm Prediction Center Norman OK
   0518 PM CDT Thu Jun 13 2024

   Areas affected...Parts of the Midwest

   Concerning...Severe Thunderstorm Watch 409...

   Valid 132218Z - 132345Z

   The severe weather threat for Severe Thunderstorm Watch 409
   continues.

   SUMMARY...Cluster of severe thunderstorms will propagate across
   southeast Iowa/northeast Missouri into western Illinois. Very large
   hail, possibly in excess of 2 inches, can be expected with this
   activity.

   DISCUSSION...An expanding cluster of severe thunderstorms has
   developed over southeast IA/northeast MO early this evening. This
   activity is evolving along a wind shift that extends from western
   IL/southeast IA/northwest MO. Latest diagnostic data suggests this
   convection is evolving within an air mass characterized by 3000 J/kg
   MLCAPE and adequately sheared for sustained rotating updrafts.
   Numerous reports of hail in excess of 2 inches have been received
   with this convection. With time this cluster should grow upscale and
   an MCS may ultimately evolve. Severe winds may become more common
   if/when the MCS matures. Subsequent movement is expected across
   western into central IL.

   ..Darrow.. 06/13/2024

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

   ATTN...WFO...ILX...LSX...DVN...DMX...EAX...

   LAT...LON   40808968 39769020 39869249 40509289 41089134 40808968