A sprawling storm system crossing the U.S. on Friday overturned semi trucks on highways and fanned dozens of wildfires in several central states, prompting evacuation orders in some communities. At least one Tornado 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 likely amid storm outbreakThe Storm Prediction Center said fast-moving storms could spawn twisters and hail as large as baseballs Friday, 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.The National Weather Service said it observed an evening tornado in the south-central Missouri city of Grovespring.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 conditionsWildfires 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.About 60 miles to the south, another fire grew to about 3.9 square miles before its advance was halted in the afternoon.The Oklahoma Department of Emergency Management 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.Firefighters had been prepositioned in certain areas, which helps authorities jump on blazes early, James said. Firefighting aircraft were also deployed in some parts of Oklahoma and Texas but were generally unable to fly due to low visibility from smoke and dust, he added.In the evening, the National Weather Service in Norman said a "complex of extremely dangerous fires" was located northeast of Oklahoma City, near Stillwater, and urged some people in the city of about 50,000 to evacuate. Officials issued mandatory evacuation orders via social media that included homes, hotels and a Walmart.Jennifer Thompson, a National Weather Service meteorologist in Norman, described the fire conditions in the central and northern parts of the state as historic and highly anomalous.Roughly 120 miles of Interstate 70 in western Kansas shut down due to blowing dust and limited visibility, and roads in the state's east were closed amid wildfires and smoke.Officials urged people in some areas of central Missouri's Camden County to evacuate due to wildfires, and the State Highway Patrol warned via social media that they were nearing homes and businesses.High winds also knocked out power to more than 220,000 homes and businesses in Texas, Oklahoma, Kansas and Missouri, according to the website poweroutage.us.Blizzard warnings in Northern PlainsThe National Weather Service issued blizzard warnings for parts of far western Minnesota and far eastern South Dakota starting early Saturday. Snow accumulations of 3 to 6 inches were expected, with up to a foot (30 centimeters) possible.Winds gusting to 60 mph were expected to cause whiteout conditions. Combined with a light glaze of ice that could fall before temperatures drop, travel in the area could be treacherous that day, the weather service said. ...read more read less