Travelers should be on the lookout Thursday for continuing traffic jams at local airports thanks to flight delays and cancellations created by Tuesday’s snowstorm.

Officials had warned Tuesday that the backup from the almost 3,000 flights canceled at Kennedy, LaGuardia and Newark Liberty airports this week might not be resolved for three days.

LaGuardia had 1,124 cancellations, about 99 percent of its flights, and Kennedy had 784 cancellations, about two-thirds of its flights, the Port Authority said.

There was heavy traffic in and around the airports Wednesday as thousands of stranded passengers tried to fly out.

“Airline passengers are strongly urged to call their carrier before going to the airports,” the Port Authority said.

A post-storm travel day usually creates jams at area airports, particularly at LaGuardia, which is in the first year of a 10-year reconstruction project that requires periodic changes in the configuration of on-airport roadways.

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When 10 inches of snow dropped on LaGuardia on Feb. 9, for example, the airport was overwhelmed with passengers and auto traffic the next day.

Video and photographs from that day showed traffic backed up onto the adjacent Grand Central Parkway and taxi and car passengers getting out of vehicles and walking on the parkway toward the airport.

On Wednesday, officials urged travelers to use mass transit to get to the airport.

Passengers going to Kennedy can get the AirTrain at Jamaica transit hub, but LaGuardia’s only mass transit is the public bus system, which experienced storm-related delays Wednesday morning.

“All Queens Local, Limited, Select and Express buses are running with delays both directions, due to inclement weather conditions,” the Metropolitan Transportation Authority said in an alert to riders shortly after 6 a.m.

The Port Authority said the Q70 express bus linking LaGuardia with the Long Island Rail Road and subways stops at Woodside and Jackson Heights would be free through Friday.