DALLAS - If you're flying somewhere for Thanksgiving, expect airports to be even more crowded this year.

U.S. airlines expect to carry 24.6 million passengers over the 12 days surrounding Thanksgiving, up 1.5 percent from last year.

The worst day: Nov. 30, the Sunday after Thanksgiving, with 2.6 million people flying on U.S. airlines.

The forecast comes from Airlines for America, a trade group representing the biggest U.S. carriers. It covers Friday, Nov. 21, through Tuesday, Dec. 2.

The group's chief economist, John Heimlich, said Thursday that rising personal incomes and job growth are helping boost demand for travel.

But the increase in passengers will be offset by additional seats and flights, so planes will be about equally full as last Thanksgiving, said a spokeswoman for the trade group. This year, American, Delta and JetBlue have increased passenger-carrying capacity - that usually means more flights or bigger planes - while United and Southwest have operated close to their 2013 capacity.

Last year, the airlines' Thanksgiving travel forecast turned out to be too high by about 3 percent. Heimlich blamed bad weather that caused widespread flight cancelations.

And historically, the crowds have been worse. Even if airlines meet this year's forecast, Thanksgiving travel would still be about 6 percent lower than it was before the recession that began in 2008.

The airlines are doing well financially by taking a go-slow approach to adding new seats and raising fares and fees. In the first nine months of this year, the nine biggest U.S. airlines reported earnings of $6.8 billion, up from $4.5 billion a year earlier, according to the trade group. U.S. airfares rose 4.7 percent this summer from the same months last summer, after adjusting for inflation.