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.

A powerful low-pressure system is likely to spawn a dangerous outbreak of severe thunderstorms in portions of the Midwest, South and East, where tornadoes, widespread damaging winds, large hail and flash flooding are all concerns.