Mesoscale Discussion 0855
   NWS Storm Prediction Center Norman OK
   0554 PM CDT Mon May 20 2024

   Areas affected...Northwestern Iowa and far southern Minnesota

   Concerning...Severe potential...Watch possible 

   Valid 202254Z - 210100Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Scattered thunderstorm development is likely over the next
   1-2 hours across portions of northwestern/northern IA and southern
   MN. Large hail up to 1 to 1.75 inches in diameter and wind gusts
   exceeding 60 mph may accompany a few of the thunderstorms.

   DISCUSSION...Recent satellite imagery indicates some upstream
   mid-level ascent, likely via PCVA, is beginning to impact locations
   east of the MO river valley over a stationary boundary. Elevated
   showers have developed over northern NE, and the cumulus field along
   and just north of the boundary is becoming agitated across
   northwestern IA and southern MN. The convective environment within
   this region is characterized by moderate instability, modest deep
   layer shear, and steep mid level lapse rates. As the evening
   progresses, a few organized updrafts may manage to develop with a
   threat of large hail and locally damaging wind gusts. There is some
   uncertainty regarding severe thunderstorm coverage across this
   region, however, so trends will be watched for a possible weather
   watch.

   ..Barnes/Thompson.. 05/20/2024

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

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

   LAT...LON   42149452 42029497 41939575 42029627 42739661 43419632
               43809554 44109495 44349428 44459386 44389296 44469241
               44259207 43809196 42869309 42499374 42149452