Even the snowplows have had trouble dealing with the snowy conditions in Indiana, where four state plows slid off slick roads near Vincennes Wednesday. Snow was falling at the rate of three inches an hour in some spots.

Blizzard warnings have been in effect across Indiana and Ohio amid wind gusts of 30 miles an hour that blanketed roads and windshields with snow. Several eastern states are reporting widely scattered outages and treacherous roads. Authorities reported scores of accidents in western Maryland.

Two passengers in a car involved in a head-on collision in Arkansas Wednesday are among six people whose deaths are linked to the storm system.

The system that brought more than 30 tornadoes to Gulf Coast states Tuesay is headed toward New England. Highway departments in northeastern states are treating roads and getting ready to mobilize with forecasts of a foot or more of snow.

The storm has forced the cancellation of hundreds of flights, stranding holiday travelers trying to return home on the day after Christmas.