OKLAHOMA CITY — A sprawling storm system crossing the U.S. on Friday overturned semitrucks on highways and fanned dozens of wildfires in several central states, prompting evacuation orders in some communities. At least three Tornadoes touched down in Missouri, and threats of more loomed for the Mississippi Valley into the night and the Deep South on Saturday.

The National Weather Service warned of extreme weather across a vast swath of the country that is home to more than 100 million people. Powerful winds gusting up to 80 mph were forecast from the Canadian border to Texas.

Nearly 150 fires were reported in Oklahoma, Andy James, Oklahoma Forestry Services fire management chief, told KOCO-TV. The State Patrol said on the social platform X that dusty winds toppled several tractor-trailers.

“This is terrible out here,” Charles Daniel, a truck driver hauling a 48-foot trailer along Interstate 40 in western Oklahoma, said of the high winds whipping up dust. “There’s a lot of sand and dirt in the air. I’m not pushing it over 55 mph. I’m scared it will blow over if I do.”

Forecasters said the severe storm threat would continue into the weekend with a high chance of tornadoes and damaging winds Saturday in Mississippi and Alabama. Heavy rain could bring flash flooding to some parts of the East Coast on Sunday.

Experts say it’s not unusual to see such weather extremes in March.

“What’s unique about this one is its large size and intensity,” said Bill Bunting of the weather service’s Storm Prediction Center in Norman, Oklahoma. “And so what that is doing is producing really substantial impacts over a very large area.”

Tornadoes hit amid storm outbreak

The National Weather Service said it observed three evening tornadoes, including in south-central Missouri city of Grovespring.

The Storm Prediction Center said fast-moving storms could spawn twisters and hail as large as baseballs, but the greatest threat would come from straight-line winds near or exceeding hurricane force, with gusts of 100 mph possible.

A tornado watch was issued until 11 p.m. for central and eastern Missouri, including St. Louis, as well as parts of Illinois and Arkansas.

Other areas at risk included parts of Iowa, Kentucky, Tennessee and Mississippi.

About 47 million people faced an enhanced to moderate severe storm threat from Madison, Wisconsin, to Birmingham, Alabama.

Forecasters grew increasingly worried that intense thunderstorms farther south will likely bring an even greater tornado threat Saturday.

The Storm Prediction Center said parts of Mississippi including Jackson and Hattiesburg and areas of Alabama including Birmingham and Tuscaloosa will be at a high risk. Severe storms and tornadoes are also possible across eastern Louisiana, western Georgia, central Tennessee and the western Florida Panhandle.

“We have a lot of confidence that we most likely will have a tornado outbreak tomorrow,” Storm Prediction Center meteorologist Evan Bentley said in an online briefing.

Wildfires break out amid dry, gusty conditions

Wildfires in the Southern Plains threatened to spread rapidly amid warm, dry weather and strong winds, and evacuations were ordered for some communities in Texas, Oklahoma, Kansas, Missouri and New Mexico.

A blaze in Roberts County, Texas, northeast of Amarillo, quickly blew up from less than a square mile to an estimated 17.1 square miles, the Texas A&M University Forest Service said on X. Crews stopped its advance by the evening.