Storm Prediction Center Mesoscale Discussion 818

   Mesoscale Discussion 0818
   NWS Storm Prediction Center Norman OK
   0230 PM CDT Fri May 16 2025

   Areas affected...northeast WI into central Upper MI

   Concerning...Severe potential...Watch unlikely 

   Valid 161930Z - 162130Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated severe gusts with small to marginally severe hail
   will be possible into early evening with high-based thunderstorms
   advancing north-northeast from northeast Wisconsin into central
   Upper Michigan.

   DISCUSSION...Scattered high-based thunderstorms have developed
   downstream of the vertically stacked cyclone over northern MN.
   Despite surface dew points only in the 40s to low 50s, storm
   development has been sustained where temperatures warmed into the
   low to mid 80s. This has yielded a deep inverted-v thermodynamic
   profile. Shear within the buoyancy layer appears weak, but the steep
   lapse rates through the troposphere will foster small to marginally
   severe hail cores. This should enhance downdrafts and could support
   strong to severe microbursts as convection spreads northeast through
   the rest of the afternoon.

   ..Grams/Mosier.. 05/16/2025

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

   ATTN...WFO...MQT...GRB...

   LAT...LON   44628927 45438876 46298799 46768742 46848709 46658619
               46098615 44328741 44198789 44158879 44268912 44628927 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN