The National Weather Service has issued a high surf advisory for Bay Area beaches until 6 p.m. today.
Large swells nearly 15 feet have already been measured by buoys along the California Coast and are expected to be sustained through the day, according to weather service officials.
Residents are advised to be cautious along the coast and to be aware of local ocean conditions. Large breaking waves and sneaker waves are possible while the advisory is in effect.
The surf advisory will affect San Francisco, Santa Cruz, San Mateo, Marin, Monterey, Contra Costa, Napa, Sonoma, Santa Clara and Alameda counties, according to the weather service.