A major winter storm headed northeast into the US Great Lakes on Friday and threatened New England after blanketing states from Minnesota to Ohio with blinding snow, sleet and freezing rain.
About 570 flights were cancelled on Friday, with 127 of them at Chicago's O'Hare airport. Kansas City Airport reopened after being closed on Thursday while crews cleared runways.
The storm dumped more than a foot (30 cm) of snow in Kansas on Thursday, forcing airports to cancel hundreds of flights and stranding motorists on highways.
Kansas City, Missouri Mayor Sly James said that about 60 buses were stuck on snowbound streets on Thursday, and even tow trucks were left immobile by the storm.
"It's still an ongoing process to get people off the roads," he told CNN.
The National Weather Service said the storm would move northeast into the upper Great Lakes over the next several days.
Sleet and freezing rain was possible in the Appalachians and mid-Atlantic states, with thunderstorms expected on the storm's southern fringe in the southeastern United States, it said.
The storm is expected to reach the East Coast this weekend, delivering heavy snow to parts of New England for a third straight weekend, from northern Connecticut to southern Maine.