It's Cherry Blossom Festival week in Washington, so guess who forgot to show up again?

The cherry blossoms, of course.

In their annual show of independence, the 500 Japanese cherry trees that Park Service officials say attract 500,000 tourists to the city for the festival have decided this year to reach their peak blooms about Easter, a week from next Sunday.

That will be a full week after the last festival event, and will make the third year in the last seven that the pink blossoms have decided to skip the festival and blooms when they feel like it.

This year's festival culminates with Saturday's Cherry Blossom Parade on Constitution Avenue, and Jim Lindsey, the National Park Service's chief horiticulturist, says there may be some blossoms by then. But he's not betting on it.

The fickle cherry blossoms like a very cold winter, which Washington didn't have, a warming trend in early March, which occurred, and springlike temperatures in late March, which have yet to arrive.

"This past weekend was really bad," said Park Service spokesman George Berklacy. "March just didn't warm up."

If the blooms on the ornamental threes do hit their peak on Easter, as Lindsey is predicting, they will be just a day later than their average peak date over the last 59 years, Berklacy said.

But the inscrutable cherry trees have also hit their peak as early as March 20, in 1921, and as late as April 18, in 1958.

"There no way the National Park Service can sync the blossoms with the festival," Berklacy said.

The Cherry Blossom Festival is Washington's single biggest annual tourist attraction, according to Berklacy. Because of the necessity of booking tour groups and making hotel reservations months in advance, the festival dates are set a year ahead of time. Next year's dates are March 30-April 4.

"We're at the mercy of Mother Nature," said Linda Regan, coordinator of this year's festival parade.

The traditional lighting of the Japanese lantern on the banks of the Tidal Basin was staged Monday night. Fourty-four high school bands are competing in a concert contest Thursday and Friday at Falls Church High School, from 8 a.m. to 7:30 p.m. A marching competition with 23 bands is scheduled on the Ellipse from 8 a.m. to 5 p.m. Friday.

Saturday's parade, running from 11 a.m. to about 1:30 p.m., will have 130 units, including six floats and a wide assortment of bands, drill teams and horse units. This year's grand marshals are Peter Marshall, host of the "Hollywood Squares" television game show, and Tom Wopat, star of the "Dukes of Hazzard" TV show.