New York City and Washington, D.C., were among the cities urging unsheltered people to get in from the cold Tuesday as the Northeast, Great Plains and Midwest faced winter storms that put tens of millions under weather alerts.

Winter storm warnings are issued "when a significant combination of hazardous winter weather is occurring or imminent."

In northern Indiana, the winter weather advisory extends from 1 p.m. Wednesday to 7 a.m. Thursday and Hoosiers can expect snow mixed with freezing rain and sleet with snow accumulations between 2-4 inches and ice up to one-tenth of an inch. Plan on slippery road conditions that could impact the Wednesday evening and Thursday morning commutes.