SUNNY SKIES FORECAST FOR 3-DAY WEEKEND.

Byline: Daily News Staff and Wire Services

Clear skies are expected over the next few days for millions of Californians enjoying the last big holiday weekend of summer.

In Los Angeles, a special attraction this Labor Day weekend will be the city's first Grand Prix auto race through the historic district around Olvera Street.

Through out Southern California, hundreds of thousands of sun lovers and trailblazers are expected to flock to local beaches and mountains, where some areas remain closed because of a recent forest fire.

The weather will be a little hot, with temperatures in the high 80s downtown and 90s in the San Fernando Valley area.

There could be scattered morning low clouds and fog along the coast, but otherwise mostly sunny, forecasters said.

``It's pretty good weather - most people will be happy,'' said Bruce Rockwell, spokesman for the National Weather Service. ``At the beaches the water is warm and temperatures are a little above normal.''

The campgrounds, hiking trails and picnic areas in Angeles National Forest north of Los Angeles are especially popular on Labor Day, so officials are advising visitors to arrive early.

Overcrowding might force the closure of some mountain roads, particularly into the Big Tujunga and San Gabriel canyons.

A number of campgrounds and trails will be closed this weekend because of a fire that has been burning in the forest since Aug. 13.

Firefighters are in the final stages of extinguishing the blaze and are worried about dangerous fire conditions elsewhere.

Because of the hot, dry weather, open campfires, barbecues and smoking are restricted to developed campsites and picnic areas only.

Parts of the Angeles National Forest that will be closed as a result of the fire include the area south of Highway 2 from Blue Ridge Road to the East Fork fire station; the East Fork Trail from the East Fork station to Vincent Saddle; Grassy Hollow picnic area and Jackson Flat campground; the lower loop of Table Mountain Campground, and the Pacific Crest Trail from Little Jimmy to Blue Ridge.

Despite rising gas prices and a wide variety of attractions nearby, a record number of people will spend Labor Day weekend 100 miles or more from home, according to the California State Automobile Club.

While hundreds of Southern Californians head north to such popular areas as Yosemite National Park and the Monterey Peninsula, tourism officials say lower air fares will also bring crowds of Northern California vacationers south to visit Disneyland, Universal Studios and Las Vegas.

About 210,000 visitors are expected to visit Las Vegas during the three-day Labor Day holiday, an 11.1 percent increase over the 189,000 people who visited the city during the 1996 holiday weekend, the Las Vegas Convention and Visitors Authority said.

Air-fare wars this summer resulted in higher than normal reservations, with a lot of last-minute bookings for Labor Day, according to the California branch of the American Automobile Association.

The AAA estimates that of the 34 million Americans traveling, 90 percent will go by automobile, light truck and recreational vehicles. Nearly 9 percent will fly, while the remainder will travel by bus, rail or ship.

Eleven percent of western U.S. residents are expected to travel over the holiday, which is unchanged from last year's AAA research.

Families flying together are advised to arrive at the airport two hours before departure to allow time for parking, security clearance and unexpected delays.

``August is the heaviest travel time of the year,'' said Tom Winfrey, a spokesman for Los Angeles International Airport.

``Allow yourself plenty of time; make sure you have identification with you for passenger check-in; and tune your radio to AM 530 for up-to-the-minute parking information,'' he advised.

Winfrey said 58 million travelers passed through LAX in all of last year, and the figure was running about 2 percent higher so far this year.

AAA offers these tips for traveling with children:

Involve children in planning the trip, such as destination and restaurant selection. The more youngsters feel part of the trip, the more they and the parents will enjoy the trip.

Check with an established travel agent who can recommend specific destinations and lodgings featuring children's activities and programs. Ask the agent to make reservations for you, saving you time and money.

Buy a few inexpensive items - small toys, books or snacks - to be wrapped in brightly colored paper and given out as treats along the way to your children.

Outfit children in comfortable clothing. Airplanes and air-conditioned cars tend to be cool, so bring a sweater or jacket for the kids.

Bring snacks and favorite toys appropriate for autos and air travel. Pack a damp cloth for those inevitable spills.

When traveling by auto, stop every two hours for a 10-minute break. Accompany children to restrooms and snack areas. Before hitting the road again, make sure everyone is buckled up and kids 12 and under are properly belted and seated in the back.