Mesoscale Discussion 0585
   NWS Storm Prediction Center Norman OK
   1041 AM CDT Mon Apr 28 2025

   Areas affected...far eastern SD...southwest MN...northwest IA...far
   northeast NE

   Concerning...Severe potential...Watch possible 

   Valid 281541Z - 281745Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Isolated convection may develop over the next couple of
   hours from far eastern South Dakota into southwest Minnesota,
   northwest Iowa, and possibly northeast Nebraska. Large hail and
   damaging gusts would be initial risk, though a tornado risk also
   could increase with time/eastern extent. Area is being monitored for
   possible watch issuance.

   DISCUSSION...Latest visible satellite/Day Cloud Phase RGB shows
   deepening cumulus developing along the surface boundary extending
   southward across eastern SD into northeast NE. Ahead of this
   boundary, broken cloudiness has allowed for filtered heating, and
   temperatures have warmed into the upper 60s to low 70s F. Meanwhile,
   a corridor of mid 60s F surface dewpoints is overspreading the
   region. Latest SPC Mesoanalysis and modified RAP forecast soundings
   suggest MLCIN has eroded, though warmer temperatures at 700 mb
   remain, which may limit instability through the 850-700 mb layer in
   the short term. Initial convection may tend to be somewhat elevated,
   though could become surface-based with time and eastward extent. 

   Hi-Res CAMs are fairly inconsistent this morning, but generally
   suggest that convection will increase ahead of the surface
   low/southward trailing boundary in the next couple of hours. Given
   favorable shear, with enlarged and favorable curved low-level
   hodographs already in place amid moderate MLCAPE, convection could
   develop rapidly once large-scale ascent increases toward
   midday/early afternoon. Initial activity may favor large hail and
   damaging gusts early in convective evolution, with an increasing
   tornado risk with time/eastward extent. Timing for convective
   initiation and initial coverage is a bit uncertain, but trends are
   being monitored and a watch may need to be issued in the next 1-2
   hours.

   ..Leitman/Hart.. 04/28/2025

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

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

   LAT...LON   43099782 44979694 45249674 45369652 45479614 45479576
               45269532 44909523 44219503 43319488 42859504 42519536
               42269607 42219634 42159708 42189767 42339802 42619804
               43099782 

   MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN