In sweltering Southland, a triple threat

A heat wave gripping Southern California will produce near-record triple-digit temperatures in inland areas Tuesday and Wednesday, while large waves and dangerous rip currents are expected at beaches from Ventura to San Diego, forecasters said.

The National Weather Service issued a high surf advisory for beaches in Ventura and Los Angeles counties from Tuesday evening through Wednesday evening. Large waves and dangerous rip currents were also expected in San Diego County.

On Tuesday and Wednesday, temperatures could hit 110 degrees in Antelope Valley, 107 in lower mountain areas from Santa Barbara to Los Angeles counties and 90 to 98 in other inland areas, the weather service said. Temperatures were expected to begin dropping Thursday.

The weather service issued an excessive-heat warning Monday, urging people to avoid lengthy exposure to the sun and to drink plenty of water.

Temperatures Monday reached 105 in Chatsworth, 98 in downtown Los Angeles and 102 in Palmdale. At the Santa Monica Pier, the temperature was a comfortable 68 degrees. In Ventura County, temperatures ranged from 76 at Point Mugu to 102 in Ojai. Temperatures in Orange County varied from 73 in Newport Beach to 97 in Yorba Linda and 98 in Lake Forest.

In the Inland Empire, Riverside Airport recorded 104 on Monday and Ontario reached 103.

Fire officials noted that the summer weather, coupled with dry, offshore winds and single-digit relative humidity predicted for mountain and inland areas, significantly increases the potential for brush fires.

“We have a lot of fuel ready to burn,” said Capt. Ron Oatman of the Ventura County Fire Department. “All it takes is a little spark.”

Along the coast, a storm in the Southern Hemisphere was expected to generate waves from 6 to 8 feet on south-facing beaches, with waves up to 10 feet at point breaks and jetties in Los Angeles and Ventura counties, according to the weather service.

On Monday afternoon, the swell was already filling in at Huntington Beach, where 7-foot waves were breaking near the pier, lifeguards said.

“The surf’s big, and the lifeguards are standing ready to help anyone who needs it,” said Huntington Beach lifeguard Lt. Mike Beuerlein. “It’s looking more like summer.”

The large waves will coincide with late-night high tides of about 6 feet, which will be caused by a full moon. “The combined effect of high surf and high tide may cause minor tidal overflow during the times of high tide,” the weather service said.

Swimmers are advised to take precautions because of dangerous rip currents that may result from the large breakers.

For much of July and early August, temperatures were below normal in coastal and inland areas of Southern California, the weather service said. The warming was being caused by a high-pressure system that had settled over the region.

robert.lopez@latimes.com