Storm Prediction Center Mesoscale Discussion 1088

   Mesoscale Discussion 1088
   NWS Storm Prediction Center Norman OK
   1222 PM CDT Thu Jun 11 2026

   Areas affected...parts of north/central Illinois

   Concerning...Tornado Watch 311...

   Valid 111722Z - 111845Z

   The severe weather threat for Tornado Watch 311 continues.

   SUMMARY...Storms may produce hail over 1.00" and locally damaging
   gusts through midday. Tornado risk is still expected to increase
   later this afternoon ahead of the upper trough.

   DISCUSSION...Scattered strong to severe storms persist just north of
   an outflow boundary associated with the MCS which moved across IA
   this morning. As expected, the more stable air mass residing ahead
   of the MCS has resulted in weakening.

   At this time, radar and surface obs continue to show the outflow
   proceeding east/southeast across northern IL, with primarily
   elevated storms with periodic strong cores traveling east/northeast.
   These storms may continue to pose a hail or locally damaging gust
   threat.

   Notably, GPS PWAT sensors continue to show increasing values
   (1.60-1.85") out of MO and into IL, as surface temperatures continue
   to rise. The cold front and shortwave trough are well to the west,
   and southwest low-level winds will persist over the warm sector. It
   is expected that the outflow boundary with the MCS will stall and
   mix/retreat later this afternoon. Shear profiles will become
   increasingly favorable for supercells and tornadoes at that time,
   with additional watches likely.

   ..Jewell.. 06/11/2026

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

   ATTN...WFO...LOT...ILX...LSX...DVN...

   LAT...LON   40188959 39919041 39989082 40249104 40579098 40919074
               41089042 41328981 41698920 41878814 41778800 41148807
               40518902 40188959 

   MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN