Doyle Rice

USA TODAY

What could be the worst ice storm in 10 years began Friday in the central U.S., as forecasters warned it will unload freezing rain on a 1,000-mile swath from the central Plains to the mid-Atlantic over the weekend.

The storm is expected to cause downed trees, extensive power outages and make driving dangerous or impossible as roads turn into sheets of ice.

Ice was already accumulating by midday Friday from Oklahoma to Indiana, the Weather Channel said, with downed trees and up to 4,000 power outages reported in Springfield, Mo.

One person died in a car wreck on a slick highway near Festus, Mo., the Associated Press said. Hundreds of schools and colleges closed throughout the area.

Forecasters expect the worst conditions to hit portions of northwestern Texas, western Oklahoma and central Kansas, where there is the potential for an inch ore more of ice to encase the region followed by 30-mph winds, AccuWeather meteorologist Eddie Walker said.

The highest forecast was for 1.42 inches of ice near Dodge City., Kan., according to the National Weather Service.

Grocery stores were selling out of bread, milk and other necessities, and hardware stores were running out of flashlights, batteries and alternative energy sources, AP reported.

Some of the big cities likely to be hit by the ice include Topeka, Oklahoma City, Kansas City, St. Louis, Indianapolis, Columbus, Pittsburgh and Washington, D.C., AccuWeather said.

Dozens of flights were canceled at airports in St. Louis and Oklahoma City on Friday as freezing rain moved in across the region. Travel will be hazardous for hundreds of miles along Interstate 35, I-40 and I-70 in the central states, said AccuWeather meteorologist Brett Rossio.

In southern Missouri on Friday morning, some areas already picked up a tenth of an inch of ice on outdoor surfaces, according to Andy Foster, a meteorologist with the National Weather Service. An ice storm warning, in place through Sunday in many areas, was already in effect for most of Kansas and Missouri and parts of Oklahoma.

Missouri's department of transportation said it could be the worst ice storm in 10 years there and said motorists should avoid travel through Sunday. “Ice is the most difficult storm to fight," said maintenance engineer Becky Allmeroth.

By Saturday, widespread freezing rain and/or sleet will extend from the central and southern Plains into the Ohio Valley and mid-Atlantic states, according to the Weather Channel. The ice storm will continue in the central Plains on Sunday.

In Kansas, up to 1 inch of ice was expected to fall in "multiple rounds" of freezing rain through Monday, making travel extremely hazardous, the weather service in Kansas City warned.

The NFL playoff game in Kansas City between the Chiefs and the Pittsburgh Steelers was moved from Sunday afternoon to that evening due to the impending storm. Temperatures are forecast to slowly rise above freezing later Sunday in Kansas City.

NFL moves Steelers-Chiefs kickoff to Sunday night due to ice storm

Freezing rain occurs thanks to a "warm air sandwich" in the atmosphere, in which a layer of warm air hovers between cold layers both above and below it. Precipitation that begins as snow at the highest level of cold air melts into rain in the warm air, then refreezes as it falls into the cold layer near the surface.

Missouri Gov. Eric Greitens called a state of emergency Thursday and said the Missouri Transportation Department started pre-treating roads and would continue to do so throughout the storm. Oklahoma Gov. Mary Fallin declared a disaster emergency for all 77 counties in the state in advance of the storm.

The Weather Channel has named the storm Winter Storm Jupiter.

Contributing: The Springfield (Mo.) News-Leader