Severe weather warnings remain in place throughout the weekend for parts of at least 20 states as extreme conditions — tornadoes, high wind gusts, large hail and severe storms — could threaten over 100 million people.

The massive storm front, spanning from the southern tip of Louisiana northward to the Canadian border, has already been tied to the deaths of at least six people Friday, including three people in Missouri from a tornado that tore through the Ozarks and three people in Texas who died in car accidents caused by dust storms near Amarillo.

At least 23 tornadoes were also reported across Arkansas, Illinois, Mississippi and Missouri Friday, the National Weather Service’s Storm Prediction Center said. On Saturday, the agency put a high-alert warning for tornadoes over the entirety of Alabama and most of Mississippi, as well as parts of neighboring states, including New Orleans and the outskirts of Atlanta.

“Numerous significant tornadoes, some of which should be long-track and potentially violent, are expected this afternoon and evening,” the National Weather Service said. According to the New York Times, Saturday marks only the third time in history that the third time in history that Storm Prediction Center has issued a high-risk warning on the second day of a storm.

“The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and several tornadoes,” the NWS added Saturday morning. “There is an additional threat of F2- EF5 tornadoes over parts of the Lower Mississippi/Tennessee Valleys, the Central Gulf Coast, and the Southeast.”

The Federal Emergency Management Agency also warned of excessive rainfall and flash flooding in the Southeast “with numerous significant tornadoes expected on Saturday afternoon and evening.”

Due to the previously dry conditions in states like Texas and Oklahoma, strong wind gusts resulted in wild fires in the Southern Plains, leading to the evacuation of some communities in Texas, Oklahoma, Kansas, Missouri and New Mexico, the Associated Press reported. More than 300,000 homes in that area were also left without power due to the gusts.

On the other end of the extreme, blizzard warnings were issued for parts of Minnesota and South Dakota, with snow accumulation and high winds likely to cause whiteout conditions.