Storm Prediction Center Mesoscale Discussion 997

   Mesoscale Discussion 0997
   NWS Storm Prediction Center Norman OK
   0539 AM CDT Sat Jun 06 2026

   Areas affected...East-central Illinois into west-central Ohio

   Concerning...Severe potential...Watch unlikely 

   Valid 061039Z - 061245Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated large hail and damaging winds are possible with a
   marginally organized cluster of storms. Surface heating will be
   needed for a greater severe threat. A watch is not anticipated in
   the short term.

   DISCUSSION...A small cluster of thunderstorms has recently
   intensified in east-central Illinois. This activity is tied to the
   shortwave trough currently moving into the lower Great Lakes region.
   Regional VAD data shows around 35-40 kt of 0-6 km shear. With
   sufficient elevated buoyancy (1000-1500 J/kg MUCAPE), some storm
   organization can be expected. Dewpoints do decrease to the the east
   of the this cluster, however. The environment will support isolated
   large hail and strong/damaging wind gusts. A couple of recent
   measured gusts were near severe (54-57 mph) in Pontiac, IL. It
   likely will be after daybreak before these storms can intensify
   further. That said, a watch is not anticipated in the near term.
   Observational trends will need to be monitored as surface heating
   increases in the coming hours.

   ..Wendt/Hart.. 06/06/2026

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

   ATTN...WFO...CLE...ILN...IWX...IND...LOT...ILX...

   LAT...LON   40048855 40408899 40888913 41258901 41478789 41328600
               41048416 40918377 40208379 39528446 39588642 40048855 

   MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN