A severe winter storm moved into the northeastern United States Wednesday, creating dangerous driving conditions for motorists and stranding thousands of travelers at airports.

The storm spawned high winds, snow and sleet from New York state into Maine. Some states, including Pennsylvania and Massachusetts, received at least 30 centimeters of snow, prompting authorities to urge residents to stay off the roads.

An aviation-tracking website said more than 1,000 domestic flights were canceled Wednesday.

The bad weather also forced the National Basketball Association to postpone a game in Indianapolis between the Indiana Pacers and the visiting Chicago Bulls.

The storm system moved into the northeastern U.S. after moving across the southern and midwestern parts of the nation on Christmas Day. Several tornadoes touched down in Alabama, Louisiana, Mississippi and Texas, damaging homes and leaving at least 200,000 people without power in Alabama and Arkansas.

At least six people have been killed in storm-related incidents.