A moderate swell out of the central South Pacific will bring high surf to the Southland's coastline Friday, along with strong rip currents and the possibility of coastal flooding, forecasters said.
The National Weather Service also said that an infusion of mid-level moisture will produce a slight chance of a shower or thunderstorm Friday afternoon and evening in the mountains of Ventura County, the Antelope Valley and the mountains of Los Angeles County, except for the Santa Monica range.
The region's heat wave, meanwhile, will ease slightly -- producing near-normal conditions -- but strong high pressure over the Four Corners region is pushing westward, which will produce a return to high, above-normal temperatures next week, according to the NWS.
The heat wave will last until at least mid-week, with the hottest days expected Monday and Tuesday, NWS forecasters said.
The NWS forecast highs of 74 today in Avalon, Newport Beach and at LAX; 82 in Long Beach; 83 in downtown L.A.; 84 on Mount Wilson; 86 in Anaheim; 88 in San Gabriel and Burbank; 89 in Pasadena; 95 in Woodland Hills; 97 in Newhall; and 102 in Palmdale and Lancaster.
Temperatures are forecast to rise a few degrees starting Saturday and revert to roughly today's levels next Friday.
"The heat wave could pose health hazards for anyone outdoors, especially for the elderly, small children and pets," an NWS advisory said. "If you plan on being outdoors, remember to remain hydrated by drinking plenty of water, wear loose-fitting clothing and a halt, and remain in the shade or indoors as much as possible.
"Never leave children or pets in cars with the windows up or cracked during the day, even for a very short time, as temperatures can quickly reach lethal levels."
Along the coast, a high surf advisory issued by the NWS will be in effect until 10 p.m. Saturday in Ventura, Los Angeles, Orange and San Diego counties.
Also in effect until 10 p.m. Saturday is a coastal flood advisory along the Orange County Coast, and NWS forecasters said that minor coastal flooding was possible over low-lying, south-facing beaches in Los Angeles and Ventura counties.
The high surf was blamed on a "moderate" swell out of the central South Pacific. Forecasters said it would produce surf of between 4 and 6 feet, with maximum sets of up to 8 feet.
"In addition, the combination of astronomical high tides and high surf will bring the potential for minor coastal flooding of exposed low-lying areas as well as minor beach erosion," according to an NWS advisory.
The weather service said that those planning to swim in the ocean in these conditions should make it a point to remain close to staffed lifeguard stations.