Dozens of tornadoes are reported from thunderstorms that lit up the radar from Wisconsin to Mississippi in the early hours Saturday.

Numerous significant tornadoes are expected Saturday afternoon and evening, with the highest risk across several states in the Deep South, forecasters say.

Millions of Americans across the country are on alert for a severe weather outbreak as violent, long-track tornadoes with damaging winds of up to 80 mph and large hail are expected across the Midwest and South with the cross-country storm moving east.