Mesoscale Discussion 0589
   NWS Storm Prediction Center Norman OK
   0529 PM CDT Mon Apr 28 2025

   Areas affected...Northeast Nebraska...southeast South
   Dakota...northwest Iowa

   Concerning...Severe potential...Watch possible 

   Valid 282229Z - 290000Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Scattered strong/severe thunderstorms are expected this
   evening. Some consideration is being given to a severe thunderstorm
   watch.

   DISCUSSION...Synoptic front is surging southeast across southeast
   South Dakota early this evening. A pre-frontal confluence zone is
   contributing to a corridor of high-based cumulus from central NE
   into extreme northwest IA. Lightning is now being observed with
   frontal convection west-north of ONL, and this activity is expected
   to gradually intensify over the next few hours as it propagates
   downstream along a zone of modest instability. Strong deep-layer
   shear suggests some supercell potential, and hail will likely be the
   primary concern, though steep boundary-layer lapse rates do favor
   gusty winds. If this activity continues to increase in
   coverage/intensity a severe thunderstorm watch may be warranted.

   ..Darrow/Gleason.. 04/28/2025

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

   ATTN...WFO...FSD...OAX...GID...LBF...

   LAT...LON   42919834 43359612 41969584 41709911 42919834 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN