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.

The largest number of deaths, 12, were in Missouri, mostly in Wayne County. Eight deaths were reported in Kansas after a 50-vehicle collision during a "severe dust storm," and six deaths were reported in Mississippi following multiple reported tornadoes.