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.

About 47 million people faced an enhanced to moderate severe storm threat from Madison, Wisconsin, to Birmingham, Alabama.

A dynamic storm that prompted foreboding predictions of dangerous weekend weather spawned tornadoes, dust storms and wildfires that killed at least 39 people and destroyed hundreds of homes and businesses.