Waves of between six and 10 feet will pound beaches in Los Angeles, Orange and Ventura counties Tuesday, as a high surf advisory would be in effect until 6 p.m.
The high surf results from a long-period west-northwest swell.
"Strong rip currents and long shore currents will create dangerous swimming conditions," the National Weather Service in a statement. "Minor coastal flooding will be possible near times of high tide on Tuesday morning."
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High tide of nearly six feet is expected in Los Angeles at 6:50 a.m. The surf pounding the Central Coast was expected be heavier than in Los Angeles County.
Forecasters warned of dangerous swimming conditions and minor flooding along the coast.
Off the coast, a small craft advisory was in effect to indicate hazardous wind and sea conditions, which are especially threatening to inexperienced sailors in small boats, forecasters said. It was intended to be in force until 3 a.m. Wednesday in some areas and 4 a.m. Thursday in others.
Also in today's forecast are mild temperatures.
The NWS forecast sunny skies in Orange County today, partly cloudy skies in Los Angeles County, and highs of 70 in Palmdale; 71 in Lancaster; 73 in Newport Beach; 74 in Laguna Beach and San Clemente; 75 on Mount Wilson; 76 in Avalon; 78 in Irvine; 79 in Saugus, Anaheim and Mission Viejo; 80 at LAX and in Fullerton; 81 in Yorba Linda; 83 in San Gabriel, Long Beach and downtown L.A.; 84 in Pasadena and Burbank; and 86 in Woodland Hills.
Crystal Egger and City News Service contributed to this report.