A series of strong jets will across the Northern Plains over the next three days. Each of those jet streaks as them move through will trigger severe storms starting today and continuing to Saturday. This will be the area where the most concentrated number of severe storms will occur the rest of the week into the weekend.
Today, severe storms will develop from South Dakota into Nebraska and will produce damaging winds and large hail. There is a risk of a few tornadoes but the main impacts will be wind and hail.
Friday the storms will focus across Iowa into Missouri where again the focus will be on high winds and large hail. That batch of storms will hit Chicago and the southern Great Lakes at night but should not be severe.
Lastly, Saturday the storms will focus once again across the eastern Dakotas into Minnesota where a tornado threat could occur. Hail and damaging winds will be the issue once again.