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