Iowa has already been hit by tornadoes.
A second day of widespread severe weather is in play, this time not just in the Midwest, but also the Southeast.
A duck boat sank during a storm on a lake in southern Missouri, killing 13 people, some of them children.
Several large tornadoes caused severe damage in Iowa on Thursday.
At least 12 people died and as many as 10,000 were hospitalized during an ongoing heat wave.