Warm and progressively more moist air will spread into the central Midwest the remainder of the afternoon. Instability will increase with CAPE values by evening up to 1300 j/kg.
That will be strong enough for some surface based supercells during initiation.
Eventually a squall line is expected that will sweep across my local area during the evening hours. You can see it hear simulated by the HRRR.
Through the early evening hours strong winds of up to 60 mph are possible if the line matures as expected. The NWS in the Quad Cities issued this regarding the potential.
SPC has this area highlighted.
I do not expect much in the way of development in my western counties before 7pm this evening. The action will then spread towards the Mississippi around 10-11pm. Stay tuned for at least some widely scattered strong to severe storms along the front after dark. Roll weather...TS