Airlines canceled 10,000 flights during severe winter storms and scrambled to rebook holiday travelers

US flight cancellations eased somewhat on Saturday, but federal officials warned that severe winter storms could disrupt air travel across the country before Christmas.

US-based airlines have canceled more than 10,000 flights since Wednesday, according to flight tracker FlightAware.

Bad weather and flight disruptions affected holiday travel plans for hundreds of thousands of people during what airlines expected to be one of the busiest periods before the pandemic.

Airlines and travelers were hard-pressed to find alternative flights before the holiday because planes were so overbooked and schedules were dropped rapidly during the weekend. The Federal Aviation Administration said the schedule reached 47,554 flights on Thursday, up from 30,875 on Saturday and just 27,997 on Sunday, Christmas Day.

This may force airlines to provide cash refunds to passengers who decide to cancel their trips altogether due to delays.

fedex And UPS warning holiday packages May arrive late due to storm.

Airlines grounded nearly 5,600 flights on Friday alone, about a quarter of the schedule, as the storm swept through cities from the Pacific Northwest to the East Coast, bringing life-threatening cold to many areas. Federal forecasters warned of dangerous road conditions from snow and low visibility.

“Wind and drifting snow could cause delays in Chicago, and wind could cause delays in and around Washington, DC, New York, Boston and Philadelphia,” the FAA said Saturday morning. “Airports serving Seattle, San Francisco and Colorado ski resorts may see delays from low clouds and visibility.”

For Saturday, more than 2,200 flights were canceled and more than 5,000 were delayed.

The FAA said delays are also possible in Florida due to the high number of seasonal flights.

Extreme cold and high winds also slowed operations at dozens of airports. Sixty-eight percent of US flights on Friday were delayed by an average of about 90 minutes, FlightAware data shows.

Disruption caused by the weather affecting all major US carriers.

jetblue airways Offered triple pay to flight attendants to pick-up trips on Saturdays.

“Winter Storm Elliott has prompted thousands of weather-related delays and cancellations across the country,” according to a JetBlue staff memo, which was viewed by CNBC. “Crewmember absenteeism rates have also increased, giving us a number of open trips for today.”

JetBlue said it would still include holiday pay for those flight attendants, under their collective bargaining agreement.

Southwest Airlineswhich has a major operation in Chicago and Denver, canceled more than 1,300 flights, about a third of its schedule, while another 2,000, about half of its schedule, were delayed.

The Southwest Airlines Pilots Association, the airline’s pilots’ union, said Thursday that 52% of pilots were rerouted.

SWAPA said ground operations managers in Denver had declared an “operational emergency” on Thursday, and required doctors’ notes to be provided for employees calling in sick.

Seattle based Alaska Airlines It canceled more than 500 flights on Friday, or 65% of its schedule, and said planes and airport ramps were covered in a thick blanket of snow, slowing its Pacific Northwest operations.

“While it is difficult, especially at this time of year, we strongly encourage guests to re-evaluate the need for their travel due to continued snowy weather and limited availability,” Friday said. “With very full flights expected over the next several days, it may take several days to accommodate guests who require new flights.”