Waves of winter weather are expected to sweep across the eastern United States this week, with a wide region of the country from the Midwest to the mid-Atlantic caught between frigid arctic air and warmer, moist air that could leave trees and roadways under a glaze of ice.

Starting on Wednesday afternoon, a storm system is expected to move in from the west, sweeping across the Ohio Valley and the mid-Atlantic. This system will clash with the lingering cold air, resulting in a widespread mix of winter weather hazards Thursday.

While light snowfall and patches of sleet are expected in some places, “freezing rain and ice accumulation are expected to be the predominant hazards, potentially leading to dangerous travel conditions,” said Bob Oravec, a meteorologist with the National Weather Service.

The heaviest icing is forecast for western Maryland, northern West Virginia, and central and southern Pennsylvania, where ice accumulations exceeding a quarter of an inch may damage trees and lead to power outages. Ice storm warnings were in effect for these areas until noon Thursday.

Winter weather advisories also stretched over large portions of the Midwest, Appalachians and Northeast. The weather service office in State College, Pennsylvania, predicted a long period of sleet transitioning to freezing rain into Thursday morning, with the greatest accumulations expected in the south-central and eastern part of the state.