SEATTLE — Sea-Tac International Airport expects a busy travel day Monday with the combination of straggling holiday travelers and a storm that's barreling toward the East Coast, causing flight delays across the country.

The airport recommended travelers plan for congested drive times, pick up passengers in arrivals, and consider using public transportation to get to the airport.

Before Thanksgiving, the Transportation Security Administration (TSA) predicted an estimated 26.8 million passengers would go through security checkpoints between Friday, Nov. 22 and Monday, Dec. 2, which is a 4% increase over last year. TSA spokesperson Lorie Dankers said Sunday that those predictions have been accurate.

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In addition to an uptick in travelers for Thanksgiving, a powerful storm is complicating air traffic nationwide.

A nor'easter could drop 10 to 20 inches of snow from Pennsylvania to Maine by Tuesday morning. Heavy snow was possible in the Appalachian Mountains down to Tennessee and North Carolina. 

More than 180 flights into or out of the U.S. were canceled Monday morning, with more than 450 delays. At least 68 flights out of or into Sea-Tac Airport have been delayed, according to Flight Aware, which tracks flight delays and cancellations.

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The Associated Press contributed.