Storm Prediction Center Mesoscale Discussion 1253

   Mesoscale Discussion 1253
   NWS Storm Prediction Center Norman OK
   0458 PM CDT Wed Jun 11 2025

   Areas affected...portions of northern Iowa

   Concerning...Severe Thunderstorm Watch 408...

   Valid 112158Z - 112330Z

   The severe weather threat for Severe Thunderstorm Watch 408
   continues.

   SUMMARY...Severe wind should continue over the next couple of hours
   with ongoing supercells, especially if they can merge their cold
   pools to support MCS upscale growth. A couple instances of severe
   hail may also occur.

   DISCUSSION...At least one supercell, with a history of wind damage
   and gusts around 70 mph, along with sub-severe hail, continues to
   track along a baroclinic boundary. Some of the latest MRMS mosaic
   radar data depicts other robust thunderstorms near the ongoing
   supercell, which may be in the process of merging. If these storms
   merge into an MCS while traversing this boundary, additional severe
   gusts are likely, accompanied by a secondary threat of large hail.

   ..Squitieri.. 06/11/2025

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

   ATTN...WFO...DVN...ARX...DMX...

   LAT...LON   42339185 42389393 42569430 42759454 42899450 43229412
               43509259 43469148 43269114 42849096 42559102 42429117
               42339185 

   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN