Storm Prediction Center Mesoscale Discussion 1396

   Mesoscale Discussion 1396
   NWS Storm Prediction Center Norman OK
   0854 AM CDT Sat Jun 21 2025

   Areas affected...northern Lower MI

   Concerning...Severe potential...Watch possible 

   Valid 211354Z - 211530Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Isolated large hail and locally strong gusts will remain
   possible into midday with elevated thunderstorms spreading across
   the northern Lower Michigan vicinity.

   DISCUSSION...Within the corridor of strong lower-level warm theta-e
   advection, a recent uptick in convective intensity has occurred
   across northern Lake MI and adjacent portions of northern
   Lower/southern Upper MI. The 12Z APX sounding sampled moderate
   elevated buoyancy with weakness in the mid-level hodograph. But the
   upstream GRB sounding sampled substantially stronger mid-level
   westerlies, which have recently overspread northern Lower MI per the
   APX VWP data. This will support embedded supercell structures
   despite convective mode likely to remain dominated by
   clusters/short-line segments. While the mode should temper overall
   hail magnitudes to an extent, around golf-ball size hail is
   possible. Relatively cooler surface temperatures ahead of this
   activity and the elevated character should also subdue the overall
   wind damage threat.

   ..Grams/Bunting.. 06/21/2025

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

   ATTN...WFO...APX...

   LAT...LON   45758385 45338326 44988325 44858361 44948467 45008541
               45048620 45238673 45708612 45938551 45998489 45758385 

   MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN