A tornado watch is in effect for parts of northern Texas until 11 p.m. Monday, according to the National Weather Service (NWS) in Fort Worth. Forecasters warn that storms moving into the area this evening could bring large hail,

Monday is probably the peak, but a storm risk shifts eastward Tuesday. Cities in the highest risk for tornadoes include Minneapolis and Rochester in Minnesota.

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.