Airlines canceled more than 1,300 flights scheduled for Friday as a massive winter storm sweeps across the U.S. with heavy snow and sleet in the forecast, followed by bitter cold.

More than 400 U.S. flights were canceled on Friday, with 1,325 canceled from Saturday’s schedule, according to flight-tracker FlightAware. The majority of Saturday’s cancellations were at Dallas/Fort Worth International Airport, with 900 scrubbed flights, and at Dallas Love Field, with 139 cancellations, each about half of the day’s schedule.

Airlines routinely will cancel flights ahead of a major storm to prevent planes, passengers and crew from getting stranded, which can worsen disruptions after severe weather moves out.

American Airlines

, Delta Air Lines