Monday is probably the peak of this event, but a concerning storm risk shifts eastward Tuesday. Cities in the highest risk for tornadoes include Minneapolis and Rochester in Minnesota and La Crosse in Wisconsin.

Millions in the Upper Midwest face the possibility of a severe thunderstorm outbreak Monday—the start of several days of extreme weather threats across the country this week.

The severe weather is typical for this time of year but also unpredictable. Forecasters said Texas may see hail as large as baseballs.