A powerful winter storm system will again snarl air traffic in the Northeast on Thursday, canceling hundreds of flights as travelers try to get home after the Christmas holiday.

Winter storm advisories are in place from central Pennsylvania to Maine, with snow accumulations of up to a foot expected by Friday morning, according to CNN meteorologist Bonnie Schneider.

A tracking website said many flights across the country have been called off for weather and mechanical reasons. According to FlightAware.com, more than 360 flights have already been taken off the schedule for Thursday. That's in addition to about 1,780 flights canceled Wednesday.