Winter Storm Cato: East Coast Airports Fight Rain, Snow On Thanksgiving Eve

Millions of Americans trying to fly through East Coast airports on Thanksgiving Eve have been fighting a mix of rain and snow courtesy of Winter Storm Cato, and now, airports will work to catch up on all the delays Wednesday evening.

Airlines had canceled more than 700 flights in the U.S. by 6 p.m. EST Wednesday night, according to the flight tracking service FlightAware. In fact, more than 200 Wednesday flights were preemptively canceled before midnight Tuesday due to the storm, USA Today reported.

Late Monday morning, delays topped three hours at LaGuardia Aiport and Newark Liberty International Airport, FlightAware also reported. But once the rain changed to snow and crews were able to clear the runways and de-ice the planes, delays declined at most Northeastern hubs. By Wednesday evening, LaGuardia's average delays were down to about 90 minutes, but Newark's delays were still well over two hours, FlightAware data showed.

"Due to the holiday, flights will be more full and there will be fewer available seats to accommodate displaced passengers," FlightAware CEO Daniel Baker told USA Today.

Most major airlines, including American, Delta, JetBlue and US Airways issued travel advisories earlier in the week, which allowed some passengers to change their tickets without fees.

"There are flight cancelations and there are delays, so the best advice I can give to air travelers is to call ahead," said Thomas Bosco, Port Authority Aviation Director for LaGuardia Airport, during a Wednesday morning interview with The Weather Channel. "Call your specific airline and find out about the status of your flight before you come to the airport."

(MORE: These 15 U.S. Airports Have the Worst Weather Delays)

The Port Authority of New York and New Jersey, which operates Kennedy, LaGuardia and Newark Liberty airports, said it was lining up extra staff and snow removal equipment in the event of a heavy snowfall. Crews were prepared to work in 12-hour shifts if necessary, officials said.