Severe thunderstorms in Iowa and Wisconsin headed east- Tornado watch possible for the Chicago area

Tornado watch possible

The Storm Prediction Center in Norman, Oklahoma is considering issuing a tornado watch for northern Illinois that will likely include portions of the Chicago Metro area.

 Mesoscale Discussion 1176
   NWS Storm Prediction Center Norman OK
   0632 PM CDT Wed Jun 28 2017

   Areas affected...Northern IL

   Concerning...Severe potential...Watch likely 

   Valid 282332Z - 290030Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Tornado watch will likely be need soon for northern IL.

   DISCUSSION...Maturing MCS is organizing over northeast IA/southwest
   WI. Latest radar data suggests an expanding cold pool will aid
   east-southeast propagation of an elongating corridor of severe
   thunderstorms such that convection should spread south of WW377.
   Shear profiles remain supportive of storm rotation and isolated
   tornadoes can not be ruled out, though the primary storm mode may be
   clustering rather than discrete supercells.