NEW YORK, Dec. 27 (Xinhua) -- A strong winter storm slammed across the U.S. Northeast and Great Lakes regions from Friday evening to Saturday, dumping snow, crippling holiday travel and leaving tens of thousands out of power.

As of 2 p.m. Eastern Time on Saturday, more than 5,580 flights within, to or out of the United States were delayed and at least 860 were canceled, according to flight-tracking service FlightAware.

Flight delays and cancellations piled up due to severe weather, with three major airports in the New York metropolitan area among the hardest hit.

The Federal Aviation Administration estimated that flights to New York's John F. Kennedy International Airport were delayed by an average of about two hours Saturday morning.

Winter storm alerts covered areas from New York to Philadelphia, with travelers and residents warned to exercise caution from the storm.

The powerful storm came ahead of the busiest travel day of the holiday season, with 2.86 million travelers expected to fly on Sunday, according to data from the Transportation Security Administration.

Ahead of the major winter storm, the governors of New York and New Jersey declared a state of emergency, urging travelers to monitor weather conditions and road closures and follow safety protocols.

In Michigan, more than 30,000 homes and businesses were without power Saturday morning as ice weighed on trees and power lines. ■