Storm Prediction Center Mesoscale Discussion 1405

   Mesoscale Discussion 1405
   NWS Storm Prediction Center Norman OK
   0635 PM CDT Tue Jun 30 2026

   Areas affected...portions of the Michigan Upper Peninsula

   Concerning...Severe potential...Watch possible 

   Valid 302335Z - 010100Z

   Probability of Watch Issuance...40 percent

   SUMMARY...An isolated supercell that has recently developed across
   the central portions of the Michigan Upper Peninsula will pose a
   risk for all severe hazards.

   DISCUSSION...An isolated, splitting supercell has recently developed
   in Delta County, Michigan. While the left split will quickly move
   into a less favorable air mass overlying Lake Superior, a narrow
   corridor of severe potential will likely exist with the right split
   across downstream portions of the Michigan Upper Peninsula. Large
   hail and damaging wind gusts will be possible with this storm over
   the next 1-2 hours, along with the potential for an isolated tornado
   given enhanced 0-500 m SRH (approximately 100 m2/s2 per latest
   objective analysis). Cooler temperatures and increased capping
   farther east should tend to limit the longevity of this threat.

   ..Chalmers/Thompson.. 06/30/2026

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

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

   LAT...LON   46408696 46538675 46568632 46488573 46308557 46098559
               45898576 45828632 45928694 46128709 46278707 46408696 

   MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN