By Forrest Brown and Karla Cripps, CNN
Winter weather continues to disrupt holiday travel across the United States on Friday, leaving travelers facing delays and cancellations during one of the busiest times of the year.
More than 3,700 Friday flights have already been canceled as of 11 a.m. ET, after nearly 2,700 cancellations on Thursday, according to flight tracking site FlightAware.
Thursday’s cancellations represented about 11% of US-based carriers’ scheduled flights, according to FlightAware, with nearly half of flights delayed on Thursday.
Cancellations are highest Friday at Seattle-Tacoma International Airport, New York’s LaGuardia and in Chicago, according to FlightAware data.
The Federal Aviation Administration posted ground stops Friday morning for flights bound for Charlotte Douglas International Airport in North Carolina, American Airlines’ second largest hub, and Reagan National Airport near Washington, DC due to deicing.
In the Pacific Northwest, FAA notices showed flights bound to Seattle-Tacoma International Airport and Portland International Airport were also under ground stops Friday morning due to snow and ice.
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The FAA says the major air pressure changes associated with this storm will trigger high winds at airports from Boston down to Atlanta.
Airports in Chicago and Denver saw the bulk of cancellations and delays on Thursday. Chicago O’Hare International Airport was logging average delays Thursday of almost three hours due to snow and ice.
An arctic blast and a rapidly intensifying winter storm have come at an unfortunate time for travelers trying to join family and friends for the holidays.
Airlines have issued winter weather waivers allowing passengers to rebook at no cost within a limited time period. Find links to the airline waivers and more air travel strategies here.
The growing cancellations make it harder for passengers racing against the clock and weather to rebook and arrive in time for Christmas. Flights this year were already more crowded than they’ve been previously — even before the storm disrupted travel schedules.
“We hear about how travel volume is still down, five or ten percent, but what many folks might not have realized is that the number of flights in the sky is actually down more like 15 or 20 percent,” Scott Keyes of Scott’s Cheap Flights told CNN.
“The planes that are actually flying are more full today than they were pre-pandemic. That’s why there’s not as many empty seats to switch onto if you do find your flight gets canceled or delayed,” Keyes said.
Train and bus service hit, too
Amtrak has also been forced to delay or cancel passenger service for some lines in the Midwest and Northeast.
Click here for details about rail service disruptions.
In its notice, Amtrak said “customers with reservations on trains that are being modified will typically be accommodated on trains with similar departure times or another day.
“Amtrak will waive additional charges for customers looking to change their reservation during the modified schedule by calling our reservation center at 1-800-USA-RAIL.”
Meanwhile Greyhound, the largest provider of intercity bus service, issued a service alert Thursday evening indicating that trips in the Midwest or upper Northeast may be canceled or disrupted.
Greyhound said riders can call 1-833-233-8507 to reschedule.
Winter weather is also impacting the services of regional intercity bus company Jefferson Lines, which operates in 14 states.
In an alert posted on its website, the company nearly 30 routes have been canceled for Friday, with a few cancellations listed on Saturday and Sunday. Cities impacted by the cancellations include Milwaukee, Minneapolis, Duluth and Kansas City.
Affected travelers can consult the Bus Tracker or call 1-858-800-8898.
This article originally appeared on CNN.