An ice storm heading for the central United States is threatening to take down trees and power lines and create treacherous travel conditions on Friday and into the weekend, the National Weather Service said.

Ice, freeze rain and winter storm warnings were in effect for a large swathe of the Plains, from the Texas panhandle north into Iowa and east through central Indiana, the Weather Service said in an advisory.

"Significant amounts of ice accumulations will make travel dangerous or impossible," the weather service said. "Travel is strongly discouraged. Commerce will likely be severely impacted."

Depending on local temperatures, ice accumulation could be more than half an inch (1 cm), creating slick roadways especially on bridges and overpasses and possibly scattered power outages across the region, the service said.

Parts of the region could also see as much as 3 inches (8 cm) of snow later in the weekend, according to the forecast.