Travelers wait in line Friday at New York's LaGuardia Airport as a storm was expected to bring delays.
CNN  — 

You might abandon those dreams of a white Christmas once you see what it could do to your holiday travel plans.

A major storm Friday has brought a triple threat of heavy rain, high winds, snow and ice to the East Coast, and it’s already causing headaches on one of the busiest travel days of the year.

More than one-third of all Americans – 112.5 million – are expected to travel this holiday season, according to AAA’s predictions. About 102 million people will be driving, while 46 million will be flying with US airlines, according to the trade group Airlines for America.

The storm could make things harder for everyone.

Here’s what you can expect:

Flash flooding

More than 90 million people were under some type of flood warning, watch or advisory Friday from Florida to New England, according to CNN meteorologist Dave Hennen, and the rain showed no signs of abating.

It’s expected to continue over much of the eastern part of the country, with the heaviest rain forecast for the Northeast, where folks could see between 1 and 3 inches.

Washington, Philadelphia and New York City were all under a flood warning or watch Friday morning, Hennen said. And there were already reports of flash flooding in New York, where a warning remained in effect until late morning.

All three New York-area airports were reporting delays between one and two hours, Hennen said, and they were expected to increase throughout the day Friday as more travelers showed up to catch their flights.

Powerful winds

More than 50 million people were under wind advisories or high wind warnings from Florida to Maine, where wind gusts reaching 50 mph could cause scattered power outages.

Nearly 50,000 people on the East Coast were without power Friday morning, according to, with the lion’s share of outages reported in Florida.

The winds and rains were causing delays for folks flying out of Philadelphia, Hennen said. And travelers in Boston, Washington, Atlanta and Charlotte, North Carolina, could be affected as well.

The wind could also cause trouble for travelers in Seattle, where a wind storm with gusts of up to 70 mph left tens of thousands of homes and businesses without power Thursday.

Snow and ice

Winter weather advisories were in effect throughout parts of New England, Hennen said, where freezing rain could cause icy roads, complicating travel plans for folks who wanted to avoid hectic airports.

The southern Appalachian Mountains were also under advisories and could see anywhere from 2 to 8 inches of snow, according to Hennen.

Low clouds, rain and snow could also hinder travelers in Chicago and the surrounding area as colder air moves in and drops snow Saturday across the Great Lakes region.

CNN’s Katia Hetter contributed to this report.