Passengers check the departure board at Miami International Airport on Sept. 7. (Marta Lavandier/AP)

This post has been updated.

Flight cancellations are now in the thousands following Irma’s destructive path over the weekend, and more air traffic disruptions await as now tropical storm Irma treks toward Atlanta, home of the world’s busiest airport.

Delta Air Lines said Monday that it has canceled about 900 flights, more than a third from Hartsfield-Jackson Atlanta International. The airline, which has a major hub at Hartsfield-Jackson and operates about 80 percent of the flights in Atlanta, said the extremely windy conditions expected to be unleashed by Irma exceed operating limits on some aircraft.

Irma’s impact in Atlanta could disrupt the travel of thousands who pass through Hartsfield-Jackson. The airport has as many as 2,800 daily departures, and roughly 275,000 passengers each day. The airport also is a major transfer point for travel throughout the southeastern region of the United States, an area already reeling from the impact of travel disrupted by Irma’s impact.

Delta said wind shear, lightning and other weather conditions could lead to additional flight cancellations.

“As is the case at all airports, Atlanta’s five runways are aligned with the prevailing wind, which generally blows from the east or west. Aircraft are best suited to take off and land into the wind for better performance. When the wind direction is perpendicular to the runway, it’s called a crosswind and can make landing challenging and potentially unsafe,” Delta said in a morning advisory. “A slight crosswind is allowable and can be safely managed, but a 40 mph or greater crosswind, as the storm is expected to bring in Atlanta, may exceed allowable limits.”

Air traffic remains halted at airports across Florida as crews begin to assess the damage Irma left behind over the weekend.  As of Monday morning, however, airports that sustained winds of up to 100 miles per hour had not reported major destruction, and some were expected to resume flights Tuesday. The two largest airports in South Florida — Miami International and Fort Lauderdale International — said no passenger flights will arrive or depart Monday.

Both airports reported hundreds of cancellations over the weekend as Irma began its approach. In Central Florida, no passenger flights were planned at Orlando International, with more than 300 flights canceled. Along Florida’s Gulf Coast, neither Tampa International nor Southwest Florida International were expected to resume service.

Nearly 700 flights were canceled Monday at Miami and Fort Lauderdale.

Miami International officials said that the airport would remain closed Monday, but was likely to resume operations Tuesday.  Some airlines will fly crews in Monday to prepare to resume operations the next day, officials said.  But, they said, the airport will determine when to begin flights after assessing the damage.

According to a tweet by Emilio Gonzalez, Miami International’s chief executive, there were wind gusts of at least 100 miles per hour at the airport. He said there was significant water damage throughout its facilities.

Fort Lauderdale said  Monday afternoon that operations will resume at 4 a.m. Tuesday.  Travelers are urged to check with their airline for the latest flight information, airport officials say.

Palm Beach International reopened its terminal at noon Monday and announced that Delta would resume limited service. Other airlines are likely to restart service  Tuesday. Officials there expected one in-bound Delta flight.

Key West International, which was among the first to shut down, remained closed Monday.

According to the flight tracking website FlightAware.com, there are more than 4,100 flight cancellations within, to and from the United States on Monday. Southwest was the hardest hit with 745 cancellations, followed by American with 713.

Both American and Southwest airlines have a significant presence in Florida and the Caribbean. American has a hub at Miami International, and Southwest has a large operation at Fort Lauderdale. American said Sunday night that it would not resume flights at most Florida airports until at least Tuesday.

At the airport near Fort Myers, officials said the storm did not damage the runways or terminal, and roadways to Southwest International Airport are clear of debris. Spokeswoman Victoria Moreland said the airport is ready to take any flights for the recovery effort Monday, but commercial operations remain halted until power is restored to the facility.

“Until we get commercial power we can’t operate,” she said. All scheduled flights for Monday are canceled and some Tuesday flights are also canceled, she said. The day will give the airport time to get personnel as many of the facility’s 4,000 workers were affected by the storm.

“The minute we get power back we are ready to deploy,” Moreland said. “Hopefully tomorrow, tomorrow afternoon.”

Further north, at Tampa International officials said early inspections showed minimal damage after the airport sustained winds of up to 52 miles per hour and gusts of 66 miles per hour. No flights were scheduled to depart or arrive Monday.

Lori Aratani contributed to this report.