NEWARK, N.J. (AP) — The storm enveloping the northeastern U.S. is causing major headaches for air travelers.

The Port Authority of New York and New Jersey says more than 1,000 flights had been cancelled as of 8 a.m. at its three major New York-area airports.

That number included 545 cancellations at Newark Liberty International Airport, which is 45 percent of the airport's normal schedule. JFK International Airport reported 449 cancellations, and LaGuardia Airport reported 437 cancellations.

Additional cancellations are expected as the storm strengthens throughout the day Wednesday.