Over 3,000 flights have been cancelled from a major winter storm slamming the Northeast

A major winter storm slammed the New York metropolitan area on Thursday morning. Snow began falling overnight, with 6 to 12 inches expected to accumulate.

As of Thursday morning, over 3,000 flights were cancelled, according to flight-tracking website FlightAware. The majority of cancellations are occurring at airports in the Northeast, with a little over 1,400 flights cancelled coming out of LaGuardia, Newark, Boston International, JFK, and Philadelphia International.

JFK issued a ground stop at around 10 a.m. ET Thursday. The airport has cancelled 280 flights and is reporting 28 delays.

LaGuardia has reported the most cancellations, according to FlightAware. The airport has cancelled 61% of its flights, but has only reported two delays.

At 8 a.m., the New York City subways and buses were running without service disruptions, but the Metropolitan Transit Authority reported delays on bus routes in the city's boroughs.

The MTA also advised drivers to proceed carefully on bridges.

New Jersey Transit reported delays on commuter rails lines and informed passengers that system-wide cross-honoring of tickets would be underway for the duration of the storm.

At the airports, some flights into and out of John F. Kennedy International, LaGuardia, and Newark Liberty International had been canceled ahead of the storm. According to the Federal Aviation Administration, Newark was under a ground stop, but operations were unaffected at JFK and LaGuardia.

We'll update this story throughout the morning.

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