Storm Prediction Center Mesoscale Discussion 1440

   Mesoscale Discussion 1440
   NWS Storm Prediction Center Norman OK
   0126 PM CDT Thu Jul 02 2026

   Areas affected...central/eastern South Dakota into far western
   Minnesota.

   Concerning...Severe potential...Watch possible 

   Valid 021826Z - 022000Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Increasing supercell threat over the next 1 to 2 hours.

   DISCUSSION...A region of ascent associated with a mid-level
   shortwave trough pivoting out of Nebraska and into southern South
   Dakota has now interacted with the outflow boundary from morning
   convection across south-central South Dakota. 2500 to 3000 J/kg
   MLCAPE in this region will support robust updraft development.
   Moderate to strong deep-layer shear (40 to 45 knots) will support
   supercell storm mode. The biggest question will be storm longevity
   in the short term. An earlier supercell across central South Dakota
   eventually became disconnected from the outflow boundary as it moved
   south. This boundary is still moving south, but somewhat slower than
   earlier with warming on the cool side of the boundary. Therefore,
   the potential for one or more supercells to latch on to this
   boundary is likely higher now. If it appears storms will remain
   rooted to the boundary, a severe thunderstorm watch may be needed.
   However, it remains possible these early storms move quickly into
   the more stable airmass and are only short lived. Any mature
   supercells which develop will have a threat for large hail, severe
   winds, and perhaps a tornado. 

   The outflow boundary across eastern South Dakota and far western
   Minnesota has mostly stalled with some towers noted on satellite
   imagery. A few supercells may develop within this area as mid-level
   ascent approaches. If these supercells develop, it might also
   necessitate a severe thunderstorm watch.

   ..Bentley/Hart.. 07/02/2026

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

   ATTN...WFO...MPX...FGF...FSD...ABR...UNR...

   LAT...LON   43369922 43600007 43980079 44380111 44700108 44670035
               44679906 44969797 45239696 46129644 46279534 45399547
               43719685 43279807 43269875 43369922 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN