NEW YORK • Americans may need an extra helping of patience for the coming Thanksgiving weekend.
This year, the number of travellers expected to travel by road or air to celebrate with family and friends will be the biggest in a decade, after a prosperous year for many.
The weather could complicate the journey in many parts of the country, as a record-breaking cold snap blankets much of the north-east on Thanksgiving Day today.
In northern California, meanwhile, heavy rain threatens to bring mudslides.
From Tuesday, more than 54 million people are expected to travel 80km or more for the traditional feast - the highest travel volume for the period since 2005.
The influx is expected to lead to heavy traffic on highways, airports, railroads and waterways, said the American Automobile Association (AAA), the largest automotive advocacy group in the United States.
Mr Bill Sutherland, a senior vice-president at AAA Travel, in a statement, said: "Consumers have a lot to be thankful for this holiday season: higher wages, more disposable income and rising levels of household wealth. This is translating into more travellers kicking off the holiday season with a Thanksgiving getaway."
Those travelling by air should expect long security lines, while those driving to their Thanksgiving destinations should plan for major traffic tangles, AAA said.
Number of Americans expected to travel 80km or more for the traditional Thanksgiving feast - the highest travel volume for the period since 2005.
Transportation analytics firm Inrix said drivers in San Francisco, New York City and Boston are likely to experience the worst delays, with their journeys expected to take nearly four times the usual duration.
Weather could disrupt travel in California, where there will be a substantial risk of heavy rain today, said Mr David Roth, a meteorologist from the National Weather Service.
After the worst wildfires in the state's history, downpours may trigger mudslides on the scorched slopes north of Sacramento and elsewhere, which have been denuded of trees.
Many other parts of the nation, meanwhile, will have a bitterly cold but clear holiday, weather forecasters said.
Boston could endure the coldest Thanksgiving on record, Mr Roth said. A forecast high of minus 6.1 deg C would break the record of minus 4.4 deg C set on Thanksgiving Day in 1901.
Yesterday, light snow was expected to fall in New York, though it was not expected to stick, while a couple of centimetres will likely accumulate in Boston, Mr Roth said.
Wind gusts of up to 64kmh could affect Thanksgiving parades in the north-east, including the world-famous Macy's Thanksgiving Day parade in New York City, but not travel itself, Mr Roth said.
If sustained winds exceed 37kmh, city guidelines may force Macy's organisers to lower the height at which the parade's 16 giant balloons can fly, the New York City Police Department told reporters.
"In the morning, just prior to the start of the event, the New York City Police Department and Macy's will make a final determination on the flight of the giant balloons," said Macy's spokesman Orlando Veras.
Delta Air Lines, United Airlines, and American Airlines, among others, reported robust or even record-breaking ticket sales for the holiday travel period.
United said it expects to fly about 2.2 million travellers between yesterday and Sunday, the biggest number in its history for the period, spokesman Charles Hobart said.
And there is more bad news for Thanksgiving guests who finish their second helping of pumpkin pie, thinking that the worst of their travel woes is behind them.
Sunday, the end of the holiday weekend, is expected to be the busiest travel day of the year - on the ground and in the air.