Weather could snarl massive travel day

By the CNN Wire Staff

November 27, 2011 -- Updated 2009 GMT (0409 HKT)

Travelers make their way to the gates at the American Airlines terminal at Los Angeles International Airport

Travelers make their way to the gates at the American Airlines terminal at Los Angeles International AirportNEW: Delays of up to 45 minutes in San Francisco Airport delays are possible in the South and Midwest About 42.5 million Americans are traveling during the Thanksgiving weekend Slightly fewer people are traveling by plane compared with last year

(CNN) -- Millions of travelers could face delays and potentially dangerous driving conditions Sunday as winter weather hits parts of the country on one of the busiest travel days of the year.

"A strong cold front is triggering showers and thunderstorms from the Great Lakes to the Gulf Coast," Meteorologist Bonnie Schneider reported for "CNN Sunday Morning."

Drivers should be aware of changing conditions as rain could turn to snow showers Sunday evening, she said.

Although as of Sunday morning the Federal Aviation Administration was not listing any major delays for flights in the region, that could change during the day.

Airport delays are possible in the South and Midwest, Schneider tweeted, adding, "#HavePatience."

The FAA did show delays of up to 45 minutes in San Francisco as of Sunday morning.

Continental Airlines reported average delays of 47 minutes due to "low ceilings," which the FAA defines as "the lowest layer of clouds when over half of the sky is obscured."

Continental was also reporting possible delays due to weather in Cleveland, Cincinnati, Detroit, and Memphis, citing "reduced visibility and rain."

Nearly 42.5 million people were expected to travel for the Thanksgiving holiday this year, an increase of 4% from last year, the travel organization AAA projected.

Slightly fewer people are choosing to get to their destinations by plane compared to last year.

About 23.2 million travelers are flying during a 12-day period surrounding Thanksgiving, a 2% drop from last year, according to a forecast by the Air Transport Association of America.

The busiest air travel days for the Thanksgiving holiday period are expected to be Sunday and Monday, the association said.

Check Federal Aviation Administration flight delay information

The Transportation Security Administration says it has prepared its work force for a "smooth holiday travel experience for travelers."

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Source: CNN