Mesoscale Discussion 0575
   NWS Storm Prediction Center Norman OK
   0229 PM CDT Tue Apr 30 2024

   Areas affected...parts of eastern South Dakota...Northern Iowa and
   southern Minnesota

   Concerning...Severe potential...Watch possible 

   Valid 301929Z - 302130Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Scattered thunderstorms over eastern SD may grow upscale
   into a more organized line/cluster with time. Damaging winds and
   hail are possible, but the coverage and severity are uncertain. A
   Severe Thunderstorm Watch is possible.

   DISCUSSION...Ahead of the advancing shortwave trough, thunderstorms
   have initiated along a pre-frontal trough/convergence zone across
   parts of eastern SD and northeastern NE. North of a modifying
   outflow boundary/effective warm front, the air mass has slowly
   moistened and warmed into the low 60s F. While not overly unstable,
   heating through scattered cloud breaks and further moistening will
   continue to allow for destabilization with SPC mesoanalysis showing
   ~500-1000 J/kg of MUCAPE. Effective straight-line hodographs will
   favor a linear/cluster mode with further upscale growth from storm
   interactions likely. Given the storm mode and modest buoyancy,
   damaging winds appear to be the most likely threat. However,
   occasional hail and a brief tornado will also be possible with any
   embedded supercell/bowing structures able to develop. Buoyancy
   decreases farther east indicating some uncertainty on the coverage
   and timing of the severe risk. Still, mesoscale trends suggest
   further destabilization is likely and a downstream severe risk may
   develop. With this in mind, a Severe Thunderstorm Watch is possible.

   ..Lyons/Hart.. 04/30/2024

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

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

   LAT...LON   42249290 42419701 42539722 43629719 44289665 44089414
               43779337 43299248 43179231 42969236 42399253 42309263
               42249290