A Tornado Outbreak is likely across parts of the Midwest tomorrow (Wed, Jun 17).
Multiple rounds of storms are expected, with the morning round mostly being a wind, hail, and flooding risk. The afternoon/evening round will contain the greatest threat for significant tornadoes (EF3 ), very large hail (2" ), and damaging winds (70mph ).
There remains some uncertainty regarding the convective evolution and the thermodynamic environment, but this is a very rare parameter space for the region in June. Winter-time extreme kinematics with Spring-Summer thermodynamics (assuming sufficient destabilization) will create a very high-end environment, capable of supporting the aforementioned hazards.
Those in the risk area(s) should be prepared for a potentially significant outbreak of severe storms and tornadoes tomorrow.