Nearly 2,200 flights are canceled and thousands more have been delayed as a winter storm bears down on the Mid-Atlantic and Northeast.Flight-tracking site Flightaware.com reports that airports from Washington to Boston have been impacted Tuesday. An additional 450 flights for Wednesday are already canceled, AP reported.The National Weather Service says the storm could bring up to 12 inches (25 centimeters) of snow Tuesday to Philadelphia and New York, and more than a foot in Boston. Bitterly cold air with wind chills as low as 10 degrees (-23 Celsius) below zero is forecast.Schools in Pennsylvania, New Jersey, Connecticut, Virginia, West Virginia and Kentucky are sending students home early or staying closed for an extra day after the Martin Luther King Jr. Day holiday.