Storm Prediction Center Mesoscale Discussion 425

   Mesoscale Discussion 0425
   NWS Storm Prediction Center Norman OK
   0342 PM CDT Tue Apr 14 2026

   Areas affected...Parts of northeast/east-central IA...southwest
   WI...and far northwest IL

   Concerning...Tornado Watch 109...

   Valid 142042Z - 142215Z

   The severe weather threat for Tornado Watch 109 continues.

   SUMMARY...A swath of very large to giant hail (3+ inches in
   diameter) appears likely over the next couple hours, with a few
   tornadoes also expected. The tornado risk will continue to increase
   through the afternoon into this evening.

   DISCUSSION...A dominant right-moving supercell has rapidly
   intensified immediately south of a quasi-stationary surface front
   extending across central IA, with additional storm splits evolving
   along its northern flank. This storm has recent reports of a tornado
   and 1.75 inch hail. Ahead of this storm, a strongly unstable air
   mass (around 4500 J/kg SBCAPE per modified 18Z DVN special sounding)
   and 50 kt of effective shear will favor continued intensification of
   this storm and additional storms forming along its flanks and near
   the surface boundary over the next few hours. Given a long/mostly
   straight hodograph (per VWP data), splitting supercells with
   dominant right-movers will pose a risk of very large to giant hail
   (some 3+ inches in diameter) and a few tornadoes. 

   With time, low-level hodographs will increase in size/clockwise
   curvature as a low-level jet strengthens through the afternoon into
   the evening. This will support an increasing risk of strong to
   intense tornadoes with any established semi-discrete supercells.

   ..Weinman.. 04/14/2026

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

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

   LAT...LON   42569317 42829282 42969226 43109053 42998994 42568984
               42248999 42009121 42049267 42289310 42569317 

   MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN