Sneaker Waves Nearly 20 Feet High Expected Along the Coast

Large and potentially dangerous sneaker waves are expected Monday from Point Reyes to Big Sur, according to the National Weather Service.

A beach hazard statement from the Weather Service covers beaches from Sonoma County to Monterey County, with an emphasis on north-facing beaches.

Large swells with waves between 13 and 19 feet are anticipated Monday afternoon and evening, according to an advisory issued by the San Francisco Fire Department, which urged the public to avoid rocks, jetties and steep beaches during the hazard period.

"Sneaker waves are deadly, larger-than-average swells that can suddenly and without warning surge dozens of feet higher up the beach than expected," according to the National Weather Service's website.

Swells can reach 150 feet up the beach and can occur after lulls of 10 to 20 minutes, giving the appearance of calm conditions, according to the Weather Service.

The advisory runs from 5 a.m. to 11 p.m.