Even before the flakes began to fall Wednesday, airlines began canceling flights in and out of Raleigh-Durham International Airport.

Southwest Airlines has canceled all flights until 4 p.m., and United had canceled 10 flights as of 6:20 a.m. Other airlines, including American, Delta and JetBlue, had canceled a smaller number of flights.

Travelers are advised to check with their airline before heading to the airport. You can also find the status of RDU flights at www.rdu.com/airline-information/flight-status/.

Those who do have a flight to catch are urged to give themselves more time to get to the airport and to arrive at least two hours before the scheduled departure. RDU officials note that some airlines, the Transportation Security Administration and airport shops and restaurants may not be fully staffed.

Forecasters expect anywhere from 3 to 7 inches of snow could fall in central North Carolina on Wednesday. But flights also can be delayed or canceled because of weather in other cities. Snow and ice were causing big delays at Atlanta’s Hartsfield-Jackson International Airport, home to Delta Airlines.