NEW YORK, Aug 29 (Reuters) - Tropical Storm Harvey has already caused thousands of flight cancellations around Houston and flooding could cripple regional aviation through the U.S. Labor Day holiday, taking a big bite out of airline profits during one of the busiest travel periods of the year.
The storm has dumped several feet of rain in Houston and the surrounding areas, forcing the temporary closure of three airports.
Airlines have canceled thousands of flights since the storm made landfall on Friday and normal operations will likely not resume until Wednesday or Thursday even under the best-case scenario.
However, conditions might put off normal service much longer, through the close of the traditionally busy Labor Day travel period, which had been projected to be even busier this year.
The exact financial impact was not yet known, but even minor storms can cost airlines millions of dollars.
A late winter storm earlier this year forced Delta Air Lines to cancel thousands of flights, resulting in a $125 million negative impact.
Since Sunday, airlines have canceled more than 5,000 flights into and out of Houston, including all scheduled flights through Wednesday, according to the website flighware.com that tracks flight delays and cancellations.
Southwest Airlines, one of the region's largest carriers, said it was possible that the storm could prohibit normal flight schedules at Houston Intercontinental and New Orleans International airports through Sept. 5.
The seven-day Labor Day travel period stretches from Wednesday, Aug. 30 through Tuesday, Sept. 5.
United Airlines, which has a major hub operation based in Houston, has canceled about 2,000 flights through Thursday. (Reporting by Alana Wise and David Shepardson; Editing by David Gregorio)