Per the SPC:
...SUMMARY... WIDESPREAD DAMAGING WINDS...A FEW TORNADOES AND LARGE HAIL ARE EXPECTED ACROSS NORTHERN ILLINOIS...SOUTHERN WISCONSIN...NORTHERN INDIANA AND SOUTHWEST LOWER MICHIGAN DURING THE LATE AFTERNOON AND EVENING ON WEDNESDAY. A SUBSTANTIAL SEVERE WIND THREAT SHOULD ALSO PERSIST WEDNESDAY NIGHT ACROSS THE REMAINDER OF SOUTHERN LOWER MICHIGAN AND INTO WESTERN OHIO.
Ample warm air and moisture advection will occur across the northern half of the state allowing for very high values of CAPE to develop. Multiple mesoscale convection systems are expected to develop associated with a deepening low pressure system and associated jet streak aloft. Low and mid-level winds will create a favorable environment for MSCs to form. The MSCs are expected to produce a bow echo which could lead to a swatch of widespread damaging winds in its path. Tornadoes, flooding rains and hail are also possible with these lines of storms tomorrow. Areas where supercells develop before conjoining into a squall line could produce violent tornadoes especially in northern Illinois.
Though a southwestward expansion of the enhanced and moderate risk areas is possible, Bloomington should currently expect some wind damage and hail reports with an isolated tornado in the area. Multiple lines of storms will likely move through starting in the morning and early afternoon and conclude in the evening hours. Stay up to date on severe watches and warnings by following our twitter page, checking our radar and severe threat monitor on our home page.