OMAHA, Neb. (AP) — Snow and freezing rain has prompted officials to close the largest school districts in Nebraska and Iowa ahead of a winter storm that's threatening the Midwest with several inches of snow.

The storm comes on the heels of the snow, frigid air and strong winds that hit the Northeast, where thousands of Rhode Island residents were without heat on Tuesday, one of the coldest days so far this year.

The National Weather Service issued weather advisories and warnings Tuesday across a large swath of the Midwest, from Kansas to Michigan.

Fatal accidents involving vehicles sliding off icy roadways have been reported in Wisconsin, Kansas and Illinois, and more than 500 flights have been cancelled at Chicago's two major airports.

Forecasters estimate up to 8 inches (20 centimeters) of snow in parts of Iowa and as many as 12 inches (30.5 centimeters) in Wisconsin, where several schools have also closed.