Storm Prediction Center Mesoscale Discussion 1157

   Mesoscale Discussion 1157
   NWS Storm Prediction Center Norman OK
   0453 PM CDT Tue Jun 16 2026

   Areas affected...Parts of southwestern lower Michigan and northern
   Indiana

   Concerning...Severe Thunderstorm Watch 338...

   Valid 162153Z - 162330Z

   The severe weather threat for Severe Thunderstorm Watch 338
   continues.

   SUMMARY...Risk of damaging winds and isolated severe hail should
   increase over the next few hours -- within Severe Thunderstorm Watch
   #338.

   DISCUSSION...Ahead of a compact midlevel shortwave trough advancing
   eastward across the Midwest, isolated cells are developing across
   southern Lake Michigan. As this activity spreads/develops eastward
   over the next few hours, a pocket of cold midlevel temperatures
   (around -20C at 500mb) and resultant steep lapse rates should
   promote some increase in updraft intensity. Despite modest buoyancy,
   the steepening midlevel lapse rates combined with strengthening
   low/midlevel flow preceding the trough (around 30-40 kt in the
   lowest 3 km AGL per nearby VWP) should promote damaging gusts and
   isolated severe hail with a mix of cells and small clusters.

   ..Weinman.. 06/16/2026

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

   ATTN...WFO...IWX...GRR...

   LAT...LON   41508678 41818676 42698635 42938598 42888564 42668523
               42148501 41628520 41288554 41238606 41328652 41508678 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN