Balmy Holiday Weekend Expected

The holiday weekend will begin with comfortable temperatures beneath a blanket of haze and smog, but an upper-level cold front that should move in Sunday will help clear the skies, forecasters said.

Morning low clouds and fog will actually begin diminishing on Saturday, particularly in the inland valleys, said Dave Beusterien, a meteorologist with WeatherData Inc., which provides forecasts for The Times.

High temperatures will range from the upper 60s along the coast to the low and mid-70s inland, Beusterien said. As the cold front begins to move south across Southern California Sunday afternoon, inland areas will begin to cool, he added.

“That will help to disperse the haze that we’ve been experiencing the last few days but it will not be noticeable until Monday,” Beusterien said, when temperatures will drop to the mid- to upper-60s along the coast to the upper 70s inland.

With warmer weather expected in Orange County during the beginning of the three-day weekend, lifeguards along the county’s 42-mile coastline said they are expecting large crowds.

Water temperatures have ranged from 64 to 68 degrees along the coast with air temperatures from the low 50s at night to 68 or 70 degrees during the day, Huntington Beach Lifeguard Supervisor Robert Thomas said. Surf is running 2 to 3 feet from the southwest, but is”nicely shaped,” he said.

Meanwhile, organizers for Garden Grove’s Strawberry Festival are expecting 250,000 people during the annual celebration that begins today at 1 p.m. and continues through 9 p.m. Monday. The traditional Strawberry Parade begins Saturday at 10:30 a.m.

Elsewhere, high temperatures Sunday and Monday will be about 3 degrees cooler in San Bernardino, Riverside and Ontario, and the northern deserts could see drops of between 5 and 10 degrees, Beusterien said.

By Monday, as back yard grills swing into action for Memorial Day, the mercury will settle in the mid-60s to low 70s along to coast. Inland areas will be slightly warmer as highs reach the mid- to upper 70s.

The upper-level storm system heading this way will lower temperatures but produce no precipitation, Beusterien said. But it will help clear the air of pollutants.

An inversion layer at about 2,000 feet above the Los Angeles Basin on Thursday reduced visibility to about 3 miles in places, Beusterien said. What essentially happens with an inversion layer, Beusterien said, is air at upper altitudes is as warm or warmer than the surface temperature.

“If air is cooler at the surface than it is at 3,000 feet, the surface air does not rise,” he said.

But the cold air associated with the upper-level storm will “lift the air in front of it, meaning the smog and haze should diminish by Sunday,” he said.

Boaters will find light and variable winds of about 15 knots over the weekend from Point Conception to the Mexican border. Three-foot seas will have west to southwest swells.