Storm Prediction Center Mesoscale Discussion 463

   Mesoscale Discussion 0463
   NWS Storm Prediction Center Norman OK
   0806 PM CDT Thu Apr 17 2025

   Areas affected...Northwest Iowa into south-central Minnesota

   Concerning...Severe Thunderstorm Watch 140...

   Valid 180106Z - 180230Z

   The severe weather threat for Severe Thunderstorm Watch 140
   continues.

   SUMMARY...A few stronger elevated storms may produce marginally
   severe hail.

   DISCUSSION...On the eastern edge of a plume of steep mid-level lapse
   rates, convection has formed behind the cold front due to weak warm
   advection over the boundary. 40-50 kts of effective shear will
   promote some risk of large hail with these storms. However, limited
   elevated buoyancy will limit the overall threat.

   Though parts of north-central Iowa are still ahead of the cold
   front, surface cooling has already contributed to an increase in
   MLCIN. The potential for development along/ahead of the front would
   appear to be low. If storms do develop, a similar hail and isolated
   wind damage threat would exist prior to the front undercutting
   convection.

   ..Wendt.. 04/18/2025

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

   ATTN...WFO...MPX...DMX...FSD...OAX...

   LAT...LON   42269651 42239689 42429702 43609613 44069510 44229467
               44249410 44239352 44079339 43379446 42549583 42339629
               42269651 

   MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN