Heat, Humidity Bake O.C.; Little Relief in Sight

The sauna that is August in Southern California set in with a vengeance Thursday, baking Orange County in a haze of record-breaking heat from the inland canyons to the beaches.

A sweltering 100 degrees was recorded at Irvine Ranch, 99 degrees in Lake Forest and 98 degrees in Tustin--all surpassing the 96 recorded in Orange County on Aug. 11, 1933, a day highlighted by a meteor shower that was seen in the county, according to an almanac compiled by local historian Jim Sleeper.

Ironically, a meteor shower was expected late Thursday night into early this morning.

“It was like an oven,” Fullerton Police Cadet Dan Allen, 21, said. “It was warm. I was running my air conditioner.”

And forecasters say there is little relief in sight, with highs in the hottest parts of the county today nearing triple digits: 97 in Anaheim and Irvine and 95 in Lake Forest. It was expected to top out at 93 in Santa Ana; San Juan Capistrano, 86; Laguna Beach, 83; Dana Point, 80; and Newport Beach 75.

Temperatures climbed into the mid-90s throughout much of inland Orange County on Thursday, the fourth straight day the mercury has passed the 90-degree mark, said Marty McKewon, a meteorologist for WeatherData, which does forecasts for The Times.

Other highs included 92 in Santa Ana and 76 in Newport Beach.

Even beach-goers seeking breezy respite up and down the Southern California coast were greeted instead with blasts of 90-degree-plus heat. Temperatures in balmy San Diego hit 86 degrees, breaking the second local heat record in two days.

In Dana Point, it was 84 degrees on the water, and hotter on land, where laborer Jose Salcedo toiled on Pacific Coast Highway. Amid the record-breaking heat and almost intolerable humidity, Salcedo was comforted by two best friends: his baseball cap and a water jug.

“You just have to keep drinking water,” said Salcedo, 35, a Santa Ana resident who was helping to repair a crumbled hillside at the southern tip of Dana Point.

His fellow worker, Jerry Salgado of Orange, added another heat-beating device--a bandanna hugging his scalp.

“It keeps the sweat out of my eyes,” said Salgado, 34. “The only shade we’ve got is the visors on our caps.”

The moisture from tropical storm Hector that was bringing clouds into the county “has all moved to the east,” McKewon said, adding that the thunderheads seen above the San Bernardino Mountains Thursday were evidence of scattered showers in the eastern deserts.

“It’s going to stay hot,” he said.

Hector not only brought clouds and humidity to the county, but a south swell that was increasing Thursday, particularly in Newport Beach. For surfers, the point breaks at 18th Street and 56th Street were breaking best, said Newport Beach lifeguard Lt. Jim Turner.

“The surf is about three to five feet today, and it’s been good for the last couple of days,” Turner said. But the waves kept lifeguards busy with more than 80 rescues a day Wednesday and Thursday, he said.

The combination of the increasingly heavy surf and a strong southerly current caused Huntington Beach lifeguards to execute several mass rescues throughout the day Thursday, said Lt. Mike Beuerlein.

As many as a dozen people were rescued at a time, although no one was seriously hurt, he said.

“The side current pushes quite a few swimmers into rip currents,” Beuerlein said. “We just had five lifeguards in the water at one time between towers 3 and 5. And that wasn’t the first time today.”

The humidity that lingered throughout the county Thursday is expected to subside today and this weekend, McKewon said. Thursday started out at 85% humidity in the county at 7 a.m. and, by 2 p.m., had tapered off to a more typical 27%, McKewon said.

For those wilting in the heat, the good news is that an increasing onshore wind should cool the coasts today, perhaps three or four degrees, McKewon said.

But anyone traveling inland should expect to be using the air conditioner or a portable fan. Places like Burbank, Lancaster and Palmdale, where the Mercury topped 100 degrees Thursday, are expected to be in the upper 90s today, McKewon said.

Van Nuys, where it was 107 degrees Thursday, will again jump over 100 today, he said.

“The air mass is basically stagnant right now. You’re just getting intense heating,” McKewon said.

Over the weekend, it will remain warm and sunny with patchy low clouds at the coast in the morning and at night, McKewon said. Highs will stay in the 70s to low 80s at the coast, and up into the mid-90s inland, he said.

Unlike areas of the San Gabriel Valley, where air quality hit hazardous levels Thursday, smog levels were generally low throughout Orange County, according to the South Coast Air Quality Management District.

McKewon said the heat wave is due to a strong high pressure system. The system is supposed to be over the Texas Panhandle this time of year, but instead has migrated westward.

Because the system suppresses the down flow of air, it inhibits the formation of clouds, “allowing full solar heating over the Southern California area,” he said.

To make matters worse, the offshore airflow that normally moderates temperatures is almost nonexistent. “It’s common in the summer to have a low-pressure system over the deserts, and this causes air to blow in from the ocean toward the lower pressure,” McKewon said. “This cools off the coast and, to a certain extent, the valleys.

“But the air mass is basically stagnant right now. You’re just getting intense heating.”

It’s Hot, Hot, Hot

While the thermometer hit a record 100 degrees at an Irvine Ranch weather station, the combination of temperature and humidity--measured by the heat index--made it feel hotter. Here is how the temperature recorded this week at WeatherData’s Tustin station compares to record highs in previous years:

Humidity Temperature Recorded high (date) Monday 55% 84 97 (Aug. 8, 1950) Tuesday 41% 93 97 (Aug. 9, 1965) Wednesday 35% 94 95 (Aug. 10, 1965) Thursday 28% 98 90 (Aug. 11, 1971) Today* 31% 98 98 (Aug. 12, 1991) Saturday* 25% 94 100 (Aug. 13, 1983) Sunday* 35% 92 97 (Aug. 14, 1983)

* Forecast

Heat Index: Here’s How Hot It Feels

The heat index is derived from a formula that involves air temperature, relative humidity and the body’s ability to cool itself. For example, today the temperature in Tustin is expected to reach 98 degrees with 31% humidity. That makes you feel as though the temperature is really 101.

Humidity Temperature 90 91 92 93 94 95 96 97 98 99 100 25% 88 89 91 93 94 95 96 97 98 100 102 26% 88 89 91 93 94 95 96 97 98 100 102 27% 88 90 91 93 94 95 96 98 99 101 103 28% 89 90 91 93 94 95 96 98 100 101 103 29% 89 90 91 93 94 95 96 98 100 101 103 30% 90 91 92 94 95 96 97 99 101 102 104 31% 90 91 92 94 95 96 97 99 101 102 104 32% 90 91 93 94 96 97 98 100 102 103 105 33% 90 91 93 94 96 97 99 100 102 104 106 34% 90 91 93 94 96 97 99 100 102 104 106 35% 91 92 94 95 97 98 100 101 103 105 107 36% 91 92 94 95 97 98 100 102 103 106 107 37% 91 93 95 96 98 99 101 102 104 107 108 38% 91 93 95 96 98 99 101 103 105 108 109 39% 91 93 95 96 98 99 101 103 105 109 109 40% 92 94 96 97 99 100 102 104 106 108 110

Source: WeatherData; Researched by APRIL JACKSON / Los Angeles Times