Big swell sending 25-foot waves to San Francisco Bay Area beaches

Big swell generated by storms and winds in the Pacific Ocean is delivering monster waves to San Francisco Bay Area beaches, leading the National Weather Service to issue the warning, "Never turn your back to the ocean."

The weather service issued a high surf advisory in effect through 10 a.m. Wednesday warning of large breaking waves up to 20 to 25 feet.

The advisory is for the coastal North Bay, including Point Reyes National Seashore, the San Francisco peninsula coast, San Francisco, Monterey Bay and the Big Sur coast.

"Breaking waves can sweep people off jetties and docks, and into cold and dangerous seas where hypothermia or drowning can occur within within a minute," the weather service warned. "Inexperienced swimmers should remain out of the water due to dangerous surf conditions."

Under these conditions, waves are expected to run further up the beach than they usually do and the breaking surf can catch beach walkers off guard.

"The swell is coming in from behind the storm," said weather service meteorologist Jeff Lorber. "It's created by a lot of activity in the north Pacific. The swell peaked yesterday but it's going to be enhanced today by northwesterly winds and that's going to create hazardous conditions at beaches."