More than 4000 flights have been cancelled or delayed in the US northeast as a winter storm delivered freezing rain and snow ahead of the Thanksgiving holiday, one of the year's biggest travel weekends.
Rain was falling in Boston, Philadelphia, New York and Washington, according to the National Weather Service, and snow and sleet was predicted for Wednesday night.
The storm is not likely to leave more than an inch or two of snow, but the weather service predicted "havoc" for travellers along the East Coast from the Carolinas up through New England.
But with the American Automobile Association predicting 46.3 million Americans will travel 50 miles (80 kilometres) or more for the holiday, most by car, the bad weather could create big problems on highways.
By late Wednesday afternoon, 671 flights had been cancelled and another 3467 were delayed. The most affected airports were Philadelphia, Newark in New Jersey and LaGuardia in New York.
Reagan National Airport in Washington was also affected, according to Flightaware.com.
United Airlines reported average delays of more than 90 minutes at JFK International in New York and 190 minutes in Newark and LaGuardia.
Flight traffic at Boston's Logan airport was also disrupted.
Many travellers opted to drive on Wednesday, taking advice from authorities to leave early to beat the winter weather.
Some airlines said certain passengers travelling to or from some northeastern US cities could change their flights without paying a penalty.
Thanksgiving, celebrated each year on the fourth Thursday in November, is a popular US holiday. Americans gather with family for a big meal that traditionally features roast turkey, cranberry sauce, sweet potatoes, and pumpkin pie.
The estimated average round-trip distance travelled in the US during Thanksgiving this year is 549 miles (884km), according to the AAA.
