A worker de-ices an airplane sitting at a gate near terminal C as a man in a tractor removes snow from the tarmac at LaGuardia Airport in the Queens borough of New York February 3, 2014. Several flights at LaGuardia Airport were delayed or cancelled due to snowy weather.???[Photo/Agencies]

NEW YORK - More than 400 flights have been canceled due to the heavy snow on Monday at the three major airports in the New York area.

The flight-tracking website FlightAware reports that by 12:00 Monday afternoon, 177 flights have been canceled at LaGuardia Airport, 75 at John F. Kennedy International (JFK) Airport, and 188 at Newark Liberty International Airport.

The National Weather Service has issued a winter storm warning for New York City, Long Island and parts of New Jersey, where 5 to 8 inches (about 12 to 20 centimeters) of snow and dropping temperatures are expected.

Many schools around the area have been closed. In New York City, public schools are open, but all school field trips and after-school programs are canceled due to the weather.

The New York City Department of Sanitation has issued a "snow alert" for Monday, with its staff beginning initial equipment readiness, including loading its salt spreaders, attaching plows when necessary, preparing tire chains and notifying supplementary personnel as needed.

Massive winter storms have dumped snow across the northeast of the country and ushered in dangerously cold temperatures, leading to at least 13 deaths in the eastern United States so far.