LOS ANGELES—Big weekend waves are expected at Southern California beaches, a result of a powerful winter storm in the western Pacific Ocean.

The National Weather Service says ocean swells were between three and five feet Saturday morning, but should grow to close to eight feet Sunday.

Beaches and jetties with western exposures are particularly at risk for sudden and dangerous breakers.

Forecasters say large swells with 24-second intervals and strong "surging-type conditions" are expected throughout the weekend.