Winter storm warnings and advisories have been issued as far east as Pennsylvania as a storm system moves across the country after dumping up to 15 inches of snow on parts of Colorado and Kansas.
St. Louis already has about a foot of snow on the ground, and the northern suburbs from 12 to 14 inches, with another 1 to 2 inches expected.
Some parts of central Illinois already have received 6 to 10 inches and could receive another 1 to 2 inches. The storm also is brushing northern Oklahoma and Arkansas.
Forecasters expect the storm to reach Indiana by tonight, bringing 6 to 10 inches of snow, then move into Ohio and Pennsylvania. It could leave 1 to 3 inches in southern New York and New Jersey before it moves off the coast tomorrow night.
Two people have been killed in weather-related crashes.
About 100 flights were scrapped at Lambert Field in St. Louis.