Storm Prediction Center Mesoscale Discussion 464

   Mesoscale Discussion 0464
   NWS Storm Prediction Center Norman OK
   0950 PM CDT Thu Apr 17 2025

   Areas affected...southern Iowa

   Concerning...Tornado Watch 141...

   Valid 180250Z - 180415Z

   The severe weather threat for Tornado Watch 141 continues.

   SUMMARY...The severe threat will continue for another hour or two.

   DISCUSSION...Two mature supercells continue to move across southern
   Iowa. These supercells have now transited the best low-level
   moisture and are moving toward lesser instability. In addition,
   boundary layer cooling will continue to increase surface based
   inhibition this evening and into the overnight hours. The
   increasingly hostile thermodynamic environment should eventually
   bring an end to the severe weather threat within the next hour or
   two across southern Iowa. In the meantime, large hail, severe wind
   gusts, and perhaps a tornado remain possible threats with these
   supercells as their strong mid-level pressure perturbations permit
   them to persist despite the aforementioned unfavorable conditions.

   ..Bentley.. 04/18/2025

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

   ATTN...WFO...DMX...OAX...

   LAT...LON   40769367 40769404 40779474 40859506 41099495 41459454
               41509326 40849309 40769367 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN