Storm Prediction Center Mesoscale Discussion 461

   Mesoscale Discussion 0461
   NWS Storm Prediction Center Norman OK
   0556 PM CDT Thu Apr 17 2025

   Areas affected...Southeast Minnesota into Northwest Iowa

   Concerning...Severe Thunderstorm Watch 140...

   Valid 172256Z - 180100Z

   The severe weather threat for Severe Thunderstorm Watch 140
   continues.

   SUMMARY...Storms in southeast Minnesota will pose a short-term
   threat for small to marginally severe hail and perhaps isolated wind
   damage. Additional development, though not certain, is possible in
   Northwest Iowa. Large hail and damaging winds would be the main
   threat in that area.

   DISCUSSION...A line of storms south of the Twin Cities will continue
   eastward. This line has shown a weakening trend over the last hour
   as it has encountered cooler/drier air. Isolated wind damage and
   small to marginally sever hail could occur with this activity, but a
   continued downward trend in intensity is expected.

   A small zone of greater surface heating ahead of the cold front is
   situated in northwest Iowa. As an upstream shortwave perturbation
   moves towards the area this evening, modestly increasing frontal
   convergence and mid-level ascent could promote an additional storm
   or two within this zone. Should storms form here, steep mid-level
   lapse rates and  40 kts of effective shear will support large hail
   and damaging wind potential.

   ..Wendt.. 04/17/2025

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

   ATTN...WFO...ARX...MPX...DMX...FSD...

   LAT...LON   42299536 42279594 42319622 42489614 42889588 43759492
               44189462 44449410 44539336 44269239 43779237 42819424
               42399481 42299536 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN