Mesoscale discussion – Severe Thunderstorm Watch over much of the Chicago area continues until 10PM CDT

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Severe storms continue to be a threat across the Severe Thunderstorm Watch area despite latest indications of a downward trend in storm intensity…following is a Mesoscale discussion issued by the National Storm Prediction Center…

The severe weather threat for Severe Thunderstorm Watch 138
   continues.

     WW 138 is currently scheduled to expire at 10PM CDT...

   DISCUSSION...Recent radar mosaic has shown a downward trend in
   convective intensity ahead of an eastward-moving cold front over
   Illinois.  This trend is likely due to prior convective overturning
   from a lead MCS over Indiana/Ohio at time, with precipitation and
   cloud cover presenting destabilization in eastern portions of the WW
   138 across northern Indiana and southwestern Michigan.  The
   resulting threat in these areas for the remainder of WW 138 remains
   unclear, although some portions of this watch may be allowed to
   expire before the currently scheduled 03Z expiration time.

   Farther southwest (in portions of central and eastern Illinois),
   moderate instability and 50 knots of deep shear suggests a continued
   severe threat, which may materialize with convection forming near
   and just east of the St. Louis metro area at this time.  It appears
   likely that at least an isolated severe threat will persist in these
   areas ahead of the front for several more hours this afternoon.