The dangerous outbreak will sweep through the Midwest, South and East through the weekend. Saturday could be one of the worst severe weather days of the year.

The threat of tornadoes is moving east into the Mississippi Valley and Deep South a day after a massive storm system moving across the country unleashed winds that damaged buildings, whipped up dust storms that caused deadly crashes and fanned more

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.