Airlines axed another 2,801 flights Wednesday, bringing Hurricane Sandy’s grand total to roughly 19,500 cancelations since Sunday.

Many of Wednesday’s cancellations were for flights into and out of New York City, where the LaGuardia airport remained closed, with no word on when it will reopen. Newark and JFK airports opened Wednesday “on a very limited operational schedule,” according to Port Authority of New York and New Jersey spokesman Ron Marsico. Most flights were for cargo and airline repositioning.

The waterfront tarmacs at both JFK and LaGuardia were flooded Monday night as a higher-than-expected storm surge crept onto runways. With the New York City subway system down, several bridges and tunnels closed and JFK’s AirTrain inoperable Wednesday, just getting to and from these airports was as much of a challenge as flying into or out of them.

Though New York has lagged behind other regions in its recovery, carriers have rebuilt schedules to other East Coast airports from Washington, D.C., to Philadelphia and Boston, bringing Wednesday’s cancellations down by more than 4,000 compared with the previous day. Nevertheless, thousands of travelers remained stranded at airports around the world awaiting flights through the nation’s busiest airspace.

Eleven major airports from Norfolk to Boston canceled at least 90 percent of their flights Monday because of the storm, and, though many flights have resumed, passengers who were originally scheduled to fly Wednesday and Thursday will get priority over those whose flights were canceled earlier in the week.

“Airlines are already filling 80 to 85 percent of their seats, on average,” said Henry Harteveldt of Atmosphere Research Group. “That leaves very little ‘wiggle room’ to serve travelers whose flights were canceled.”

For some destinations, travelers may find themselves unable to rebook their flights for several days, perhaps as much as a week, Harteveldt said.

“Depending on the airline, its fleet, the availability of crews and the airports involved, some carriers may have the ability to operate larger aircraft on some routes and flights to help move more people to and from the affected cities,” he added. “Other airlines may choose to operate ‘extra sections,’ the term used for additional flights beyond those originally scheduled, but again, this will be a function of having airplanes, crews and airport gates available to handle the additional flights.”

All major carriers have waived change and cancellation fees for the estimated 1.5 million airline passengers affected by Sandy -- though altering flight itineraries has not always been easy. Many passengers have complained of hours-long wait times to rebook. Carriers have increased staff at their call centers, but they’ve asked affected customers to try and rebook online.

Airlines typically waive ticket-change fees and cancel flights long before a hurricane arrives to help cut the number of travelers and flight-crew members stranded. Canceling flights well enough in advance also keeps planes out of the way of danger and allows airlines to resume service faster after the storm passes.

Those whose flight plans were squashed by the storm may finally have a bit of luck with the rails. Amtrak resumed some service in the Northeast Wednesday, though flooded train tunnels will prevent service to and from New York Penn Station. The Keystone trains in Pennsylvania and Downeaster service between Boston and Portland, Maine, will run Wednesday, though Amtrak has not said when its regional services between New York and Boston or its Acela Express along the Northeast Corridor will resume.

Many regional carriers like NJ Transit, Metro-North and the Long Island Rail Road remain out of service with no timetable for when operations will resume.

For those looking to get around by car, rental rates have gone up considerably, according to Orbitz. Fees are up 14 percent in New York, 17 percent in Boston, 24 percent in Washington and a whopping 50 percent in Philadelphia.

With water and debris blanketing the roads, train tracks and runways of the northeast, it’s clear now that Sandy’s impact on travel through the nation’s most populous corridor will be long-lasting.