Tornado warnings posted in U.S. midsection

OKLAHOMA CITY -- Strong thunderstorms capable of dropping grapefruit-sized hail and producing a few intense tornadoes popped up across the central U.S. on Tuesday after forecasters warned millions of people faced a significant danger.

Businesses set out to protect their goods ahead of storms, while school districts sent children home early, hoping they would make it to safety before twisters, 4-inch hail and 80 mph winds raked the landscape.

"This is a particularly dangerous situation," the U.S. Storm Prediction Center alerted in red type in an afternoon advisory. It uses such language on only about 7 percent of its tornado watches.

Forecasters predicted a 90 percent chance of tornadoes and said 80 percent could have winds above 111 mph in much of Oklahoma and northern Texas.

Residents of Topeka, Kansas, eyed the sky nervously during rush hour Tuesday afternoon after forecasters warned a supercell thunderstorm could produce a tornado.

A rope tornado touched down southwest of Mayfield, Kansas, near the Oklahoma border south of Wichita. No injuries were reported.

In addition to Kansas and Nebraska, where forecasters were 80 percent sure they were coming, severe thunderstorms and strong wind gusts also were predicted for Mid-Atlantic states that were holding primary elections Tuesday.

In all, about 70 million people nationwide were at a slight risk or higher of severe weather.

George Eischen, 51, spent Tuesday morning moving vehicles off the lot at his Chevrolet dealership in the small town of Fairview, about 100 miles northwest of Oklahoma City. Eischen said he was lining the new vehicles "bumper to bumper" in the shop and the floor of the lobby to protect them from hail.

"We've never been hit by a tornado here in town, amazingly," Eischen said. "But yeah, we've had hail. And that's the real enemy of the car dealer."

Winds gusting to 67 mph downed trees, damaged buildings and knocked out power in parts of northern and central Missouri. Workers scrambled to protect planes at the Spirit of St. Louis Airport in Chesterfield, Missouri, when the sky turned green.

"And I mean green green," aviation director John Bales said. "It was pretty violent, but luckily we didn't have any substantial damage. We saw it coming, and we were able to get most of the airplanes into hangars, so we didn't have too much hail damage."

The power company Ameren reported 28,000 outages in the St. Louis area.

Hail the size of quarters or smaller had been reported in parts of Missouri, Oklahoma, Ohio and Kansas by mid-afternoon.

Some Oklahoma school districts canceled classes Tuesday.

Associated Press writers Jill Bleed in Little Rock, Arkansas, and Jim Salter in St. Louis contributed to this report.