(CNN) -- It seems that travelers can't catch a break this winter.
This time it'll be the Northeast that takes another hit from the barrage of winter storms that has pounded U.S. airline itineraries this season. By 9 p.m. Wednesday, more than 4,000 Thursday flights had been canceled, according to FlightAware.com, as the storm system wreaking havoc in the Southeast advanced up the East Coast.
On Wednesday, the world's busiest airport, in Atlanta, accounted for the largest share of the day's flight cancellations, with more than 1,600 of the 3,300-plus cancellations across the country. About 27,000 flights were scheduled nationwide Wednesday, according to FlightAware. Charlotte Douglas International Airport in North Carolina was the second most-affected airport on Wednesday, with nearly 860 cancellations.
Mounting cancellations of Thursday flights are more evenly distributed, with hundreds in Atlanta, Philadelphia, Washington and New York area airports.
Travelers seem to have heeded warnings to stay off roads in the South for most of Wednesday, but at least one international traveler really needed to get to the airport to take off.
Austrian businessman Roland Dimai's wedding to Vlada Golovina is scheduled for this weekend in his hometown. But he almost didn't make it after traveling to Atlanta for a conference last week. After a rebooking and a cancellation, United Airlines put Dimai on one of the few Delta Air Lines flights leaving Atlanta on Wednesday, which arrived in sunny and clear Detroit in the afternoon.
Now he can make his connecting flight to Frankfurt and get to the wedding on time.
"I finally think I've found the right woman and I thought it's possible the wedding will not happen," said Dimai, laughing as he called CNN just after landing in Detroit. "I've been scared and sad and slightly hopeful to get it done."
Dimai was one of the lucky ones.
Atlanta-based Delta Air Lines canceled about 1,700 of its Wednesday flights systemwide, and had already canceled about 1,200 Delta and Delta Connection flights set for Thursday.
"We anticipate a moderate resumption of arrivals beginning mid-morning (Thursday) followed by a set of departures in the 2:00 hour ET," Delta spokesman Morgan Durrant said in a statement. "Our plan is to then gradually ramp up Atlanta operations to our usual levels through the day Thursday and into Friday."
Southwest, which also operates AirTran Airways, said both airlines have suspended operations in Atlanta through 11 a.m. Thursday.
Airlines don't like ice.
Delta and Southwest Airlines didn't wait for Wednesday's ice storm to move many of their aircraft out of Atlanta. They flew airplanes to other airports to keep them out of the path of the storm.
Winter storms do most of their damage to air travel on the ground, requiring that aircraft be de-iced while runways and taxiways are cleared and treated, all while passengers, luggage and cargo get loaded into an airplane.
"Everything slows to a crawl as personnel and ground equipment get bogged down in the slush," wrote commercial pilot Patrick Smith, who blogs about flight at Askthepilot.com, in his latest book.
"Planes, meanwhile, cannot take off with ice or snow adhering to the wings, and need to sprayed down," wrote Smith. It's not the weight of the ice "but the way it disrupts airflow over and around a wing's carefully sculpted contours.
"This can take a half hour or more per plane, and to preclude further buildup it needs to be done as close to departure as possible. And with fluid costing upwards of $5 per gallon, airlines dread snowstorms almost as much as strikes, wars and recessions. When you add in handling and storage costs, spraying a single jet can cost tens of thousands of dollars."
It's going to get worse before it gets better across the East.
The Atlanta and Charlotte airports expect frozen precipitation to continue through Thursday morning, according to FlightAware.
At least most air travelers heading through Atlanta got the message about cancellations and delays before heading to the airport. About 175 passengers spent Tuesday night at the airport, said airport spokesman Reese McCranie. "Those numbers are far less than the storm we had two weeks ago."
The stranded passengers were outnumbered by the 280 airport employees who worked overnight.
Once the storm lets up, it could take days before the airlines can get all crew and aircraft back into position.
Airline customers should check their flight status with airlines before departing for the airport. Many airlines are offering flexible, no-fee changes to travel dates.