NORMAN, Okla. » Strong storms rumbled through the Southern Plains early Thursday, missing major population centers but offering a preview of bad weather that could hit Chicago, Detroit and other big cities in the Midwest later in the day.

The Storm Prediction Center said 57 million people lived in an area with an "enhanced risk" of hail, damaging winds and tornadoes on Thursday. Tornadoes were reported Wednesday and early Thursday in Kansas, Missouri and Oklahoma, but those areas saw minimal damage.

Meteorologists and emergency managers from the high Plains to the Appalachians were on alert as the U.S. had the year’s first widespread bout of severe weather. The key message: Have a plan.

"Where to hide, emergency kits with medicines, snacks, water. Even something like sturdy shoes, gloves, long-sleeve shirts. If they get hit by a tornado they’ll find they’ll need those things pretty quickly," said meteorologist Erin Maxwell with the National Weather Service in Norman, Oklahoma.

"Know what you’re doing, and just don’t panic," Maxwell added.

Severe thunderstorms packing 70 mph winds and large hail made their way across central Missouri on Wednesday afternoon, including several capable of producing tornadoes.

Weather spotters reported a funnel cloud near Potosi in eastern Missouri at 3:35 p.m., while an hour earlier the Bates County emergency manager reported a tornado in southwest Missouri that destroyed a 60-foot machine shop.

Indiana State Police said high winds toppled a tractor-trailer on Interstate 69 near Evansville, while utilities reported a number of power outages after wind gusts reached 70 mph.

Fewer than 1 million people were covered by Wednesday’s "moderate risk" area between Wichita, Kansas, and Jefferson City, Missouri. Thursday’s worst weather was predicted in an area that included Chicago, Detroit and St. Louis, as well as those in Memphis, Tennessee, and Little Rock, Arkansas.

Areas that won’t see strong storms Thursday could see heavy rain instead.