Soaking rain and blustery winds could cause travel delays across the eastern United States on Christmas Eve, forecasters said, after fog and drizzle snarled air traffic Tuesday.
An inch or more of rain was expected to fall with steady showers from late Tuesday night through late Wednesday night, posing some moderate flooding risks. Winds are forecast to pick up Wednesday night into Christmas Day.
Backups at airports across the Northeast on Tuesday prompted Baltimore-Washington International Thurgood Marshall Airport officials to urge travelers to arrive at least two hours before flights through the busy holiday travel period. More than 2 million Marylanders are expected to travel between Tuesday and Jan. 4, the most on record, according to AAA.
The delays worked in favor of Rob and Karen Morris, who got caught in traffic Tuesday morning driving to BWI from their home in Philadelphia.
The Morrises arrived at the airport about a half-hour late — they were sure they would miss their Southwest Airlines flight to Charleston, S.C. — but an hourlong flight delay meant they had time to stop in the bathroom and rearrange their bags before going through security.
"It's the difference between stress and relaxation," Rob Morris said.
Others faced much longer delays. Robert Orr said his brother was supposed to arrive between 10 a.m. and 10:30 a.m. on a US Airways flight from Norfolk, Va., connecting through Charlotte, N.C. The 27-year-old was waiting for him outside the terminal five hours later.
Orr, who lives in Shanghai, said the two are visiting their family in Fort Meade for Christmas.
Shari Roberts, 30, of Ellicott City waited with her 6-month-old son near the security line while her husband parked their car. The Roberts' Southwest flight to Providence, R.I., was delayed an hour from 4:40 p.m. to 5:40 p.m. — a minor inconvenience, she said.
In the greater scheme of things, Roberts said, shrugging, "What's an hour?"
More than 4,100 flights were delayed nationwide Tuesday as of early evening, according to the flight data-tracking website FlightAware. That included about 80 out of BWI, or one in four flights from there. Delays built up at airports across the Northeast, including in Philadelphia, New York and Newark, N.J.
Across the country, about 98.6 million Americans are expected to make trips from Tuesday through Jan. 4, a 4 percent increase over last year and also the greatest number since 2001, AAA said. Airlines for America predicts 45 million people will fly in the U.S. during the holiday season.
Those traveling were expected to meet messy conditions.
Rain is expected to be steady across most of the Eastern Seaboard, with chances for thunderstorms in the Southeast, AccuWeather.com senior meteorologist Tom Kines said. A massive storm system moved in from the west, pulling moisture from the Gulf of Mexico northward, he said.
"Anybody traveling by land, the rain's going to be an issue," Kines said. "I'm sure there's going to be flight delays caused by rain and wind."
But temperatures are expected to be well above normal, preventing snow from falling across the East. Rain could turn to snow around the western Great Lakes, Kines said.
There is a risk of flooding in part because winter cold has hardened the ground, said Greg Schoor, a meteorologist with the National Weather Service's Baltimore/Washington forecast office. Rain forecast to fall steadily all day is also likely to cause ponding in low-lying areas, he said.
Dry weather is forecast to arrive for Christmas Day, but higher-than-normal temperatures are expected to remain, with highs expected in the lower to mid-50s. Winds gusting up to 25 mph or 30 mph are expected to make it feel colder.
Bloomberg contributed to this article.