At least sixteen people have been killed as a series of tornadoes and storms hit the US Midwest and south overnight, police said.
At least 10 people were killed in Missouri while officials were assessing the destruction from powerful thunderstorms in parts of Arkansas, Illinois, and Mississippi.
Officials in Arkansas said on Saturday morning that three people died in Independence County and 29 others were injured across eight counties as storms passed through the state overnight.
"We have teams out surveying the damage from last night's tornadoes and have first responders on the ground to assist," Arkansas Governor Sarah Huckabee Sanders said.
On Friday, meanwhile, authorities said three people were killed in car crashes during a dust storm in Amarillo in the Texas Panhandle.
Twenty-six tornadoes were reported but not confirmed to have touched down late on Friday night and early on Saturday, said David Roth, a meteorologist at the US National Weather Service's Weather Prediction Center.
"Today there is a high risk for more tornadoes across Alabama and Mississippi. The chance is 30%," he said. "That's pretty significant."
The deaths included a man who was killed after a tornado ripped apart his Missouri home.
"It was unrecognizable as a home. Just a debris field," said Coroner Jim Akers of Butler County, describing the scene that confronted rescuers when they arrived.
"The floor was upside down. We were walking on walls." Rescuers managed to save a woman in the home, Mr Akers said.
Extreme weather conditions, including hurricane-force winds, are forecast to affect an area home to more than 100 million people.
Winds gusting up to 80 mph were predicted from the Canadian border to Texas, threatening blizzard conditions in colder northern areas and wildfire risk in warmer, drier areas to the south.
High winds also knocked out power to more than 260,000 homes and businesses in Texas, Oklahoma, Arkansas, Missouri, Illinois and Indiana, according to the website poweroutage.us.
As the storms regain strength, the highest possible risk of tornadoes and severe thunderstorms is on Saturday night, forecasters said.
The storms will move east throughout the day on Saturday and could hit as far east as the Florida Panhandle and Atlanta by midnight, according to forecasters.
