Storm Prediction Center Mesoscale Discussion 1930

   Mesoscale Discussion 1930
   NWS Storm Prediction Center Norman OK
   0228 PM CDT Tue Aug 11 2026

   Areas affected...east-central Illinois into west-central and
   southern Indiana

   Concerning...Severe Thunderstorm Watch 565...

   Valid 111928Z - 112130Z

   The severe weather threat for Severe Thunderstorm Watch 565
   continues.

   SUMMARY...Damaging wind potential may increase with more recent
   thunderstorm development, which would potentially require an
   extension of the watch into portions of southwest Indiana.

   DISCUSSION...A west-to-east-oriented band of thunderstorms has
   recently intensified across portions of east-central IL into
   west-central IN, to the north of an outflow boundary from earlier
   convection. The 18Z ILX sounding is likely representative of the
   inflow environment with steep mid-level lapse rates and a moist
   boundary layer yielding MLCAPE of 2000-2500 J/kg. The current storms
   might still be slightly elevated atop a shallow surface inversion.
   However, a continued storm motion toward the more unstable
   environment should support a transition to surface-based updrafts
   with an increasing threat for damaging wind gusts as the attending
   cold pool matures. Prior to that, isolated occurrences of severe
   hail are possible.

   The severe threat is expected to largely spread southeast into the
   watch area over the next hour, so an additional watch to the west in
   IL is not currently anticipated. However, the current watch may need
   to be locally extended into southwest IN.

   ..Mead.. 08/11/2026

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

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

   LAT...LON   39828835 40558847 40708746 40588685 39728618 39098568
               38728585 38788656 39058739 39478786 39828835 

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