Storm Prediction Center Mesoscale Discussion 1891

   Mesoscale Discussion 1891
   NWS Storm Prediction Center Norman OK
   0215 AM CDT Mon Aug 10 2026

   Areas affected...parts of east central Illinois...north central
   Indiana

   Concerning...Severe Thunderstorm Watch 550...551...

   Valid 100715Z - 100915Z

   The severe weather threat for Severe Thunderstorm Watch 550, 551
   continues.

   SUMMARY...Scattered thunderstorm activity continues to develop east
   and south of the Lake Michigan vicinity, but the risk for additional
   severe weather appears to be lowering enough that a new severe
   weather watch is not anticipated.

   DISCUSSION...Lingering convection now generally spreading across and
   to the east/south of the southern Lake Michigan vicinity appears
   rooted within forcing for ascent associated with
   lower/mid-tropospheric warm advection.  This is downstream of a
   low-amplitude short wave perturbation which is forecast to continue
   across the southwestern Great Lakes region overnight.

   A small clustering of storms now to the northwest of Danville IL
   appears the lone activity maintaining roots near the surface, within
   a boundary-layer characterized by seasonably high moisture content
   including dew points in the lower/mid 70s F.  Located along a 30-35+
   kt west-southwesterly 850 mb jet axis, near-surface hodographs are
   characterized by large clockwise curvature supportive of updraft
   rotation, though there is a weakness in flow further aloft,
   particularly with south/southeastward extent from the current
   position of the stronger convection.

   As activity continues to develop east-southeastward into a somewhat
   less moist air mass, any lingering risk for tornadoes seems likely
   to diminish.  Potential for a couple of strong surface gusts may
   persist, but it is not clear that this will require a new severe
   weather watch.

   ..Kerr.. 08/10/2026

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

   ATTN...WFO...IWX...IND...LOT...ILX...

   LAT...LON   41248795 40488488 39988603 40538793 40848853 41248795 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN