The National Weather Service has predicted extreme weather across a vast swath of the US encompassing more than 100 million people, with powerful winds gusts up to 80mph (130km/h) being forecast from the border with Canada to Texas.

A sprawling storm system crossing the US on Friday overturned semitrucks on highways and fanned wildfires in Texas and Oklahoma, where officials called for evacuations in at least one town. Tornado threats loomed for the Mississippi valley into the night and the deep south on Saturday.

An approaching wildfire fueled by dry grasses and spread by strong winds prompted emergency officials to urge residents to evacuate Leedey, Oklahoma, a town of about 400 people. Meanwhile, the Oklahoma 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 48ft 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 55mph. 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 on Saturday in Mississippi and Alabama. Heavy rain could bring flash flooding to some parts of the east coast on Sunday.

Experts say it is 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.”

The Storm Prediction Center said fast-moving storms could spawn tornadoes and hail as large as baseballs on Friday. But the greatest threat would come from straight-line winds near or exceeding hurricane force, with some gusts possibly reaching 100mph.

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

Forecasters said areas also 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 would probably bring an even greater tornado threat on 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 of damaging winds and tornadoes. 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,” the Storm Prediction Center meteorologist Evan Bentley said in an online briefing on Friday.

Wildfires in the southern plains threatened to spread rapidly amid warm, dry weather and strong winds.

A blaze in Roberts county, Texas, north-east of Amarillo, quickly blew up from less than a square mile (about 2 sq km) to an estimated 12.5 square miles, the Texas A&M University Forest Service said on X.

The Oklahoma emergency management department activated its emergency operations center after several fast-moving fires that prompted evacuations of the town of Leedey in the western part of the state and in a rural area east of Norman.

High winds also knocked out power to more than 210,000 homes and businesses in Texas, Oklahoma, Kansas and Missouri, according the website poweroutage.us.

Meanwhile, the National Weather Service issued blizzard warnings for parts of far western Minnesota and far eastern South Dakota starting early Saturday. Snow accumulations of 3-6in (7.5 to 15m) were expected, with up to a foot (30cm) possible.

Winds gusting to 60mph into Saturday afternoon were expected to cause whiteout conditions. Combined with a light glaze of ice that could fall in some places before the temperature drops, travel conditions in the area could be treacherous that day, the weather service said.

The winter blast continued after snowfall of up to 3ft blanketed the Sierra Nevada earlier in the week.