WASHINGTON, April 3, (AP): Violent storms cut through a wide swath of the South and Midwest, spawning tornadoes and killing at least one person, knocking down power lines and trees and ripping roofs off homes. Dozens of tornado and severe thunderstorm warnings were issued Wednesday in parts of Arkansas, Illinois, Indiana, Missouri and Mississippi as storms hit those and other states in the evening.

Forecasters attributed the violent weather to daytime heating combining with an unstable atmosphere, strong wind shear and abundant moisture streaming into the nation’s midsection from the Gulf. At least one person was killed in southeast Missouri, KFVS-TV reported, while part of a warehouse collapsed in a suburb of Indianapolis, temporarily trapping at least one person inside.

In northeast Arkansas a rare tornado emergency was issued as debris flew thousands of feet in the air. The coming days were also forecast to bring the risk of potentially deadly flash flooding to the South and Midwest as severe thunderstorms blowing eastward become supercharged. The potent storm system will bring "significant, life-threatening flash flooding” each day through Saturday, the National Weather Service said.

With more than a foot (30 centimeters) of rain possible over the next four days, the prolonged deluge "is an event that happens once in a generation to once in a lifetime,” the weather service said. "Historic rainfall totals and impacts are possible.” More than 90 million people were at some risk of severe weather in a huge part of the nation stretching from Texas to Minnesota and Maine, according to the Oklahoma-based Storm Prediction Center.

A tornado emergency - the weather service's highest alert - was briefly declared around Blytheville, Arkansas, on Wednesday evening, with debris lofted at least 25,000 feet (7.6 kilometers), according to Chelly Amin, a meteorologist with the service. "It's definitely going to be a really horrible situation here come sunrise in the morning in those areas,” Amin said.

A tornado was also reported on the ground near Harrisburg, Arkansas, in the evening. The Arkansas Division of Emergency Management reported that there was damage in 22 counties due to tornadoes, wind gusts, hail and flash flooding. At least four people were injured, but there were no reports of fatalities as of Wednesday evening. In Kentucky, a tornado touched down Wednesday night around Jeffersontown, a suburb of Louisville, passing the Interstate 64 and Interstate 265 interchange, according to the weather service.