Giant waves are forecast to pummel the California coastline, churned up by Pacific storms sweeping across the West Coast this week. Meteorologists are warning that “tremendous wave energy” will lead to treacherous conditions at California beaches Thursday through the weekend, and high surf warnings and advisories have been hoisted up and down the coast.

In some spots, waves could be large enough to damage piers, and could cause coastal flooding and significant beach erosion. Breaking wave heights of up to 40 feet are possible along the Northern California coastline, with the peak swell arriving near high tide late Thursday morning.

“People are advised to stay out of and well away from the water, and keep a close eye on kids and pets,” the National Weather Service for the Bay Area wrote on Wednesday.


Advertisement


“These are deadly conditions that can easily overpower the strongest swimmers.” Satellite data showed waves about 42 feet high in the open ocean far offshore on Wednesday, said Alexis Clouser, a meteorologist with the Bay Area weather office in Monterey, Calif.

“These are not the highest wave heights we’ve seen, but they’re certainly on the larger side,” she said. “They are deadly due to their size and the potential run-up — our biggest concern is people getting too close to the water and potentially getting swept in.”

Waves between 10 and 20 feet and up to 25 feet high could strike parts of the central and Southern California coasts, and could flood vulnerable low-lying areas including beach parking lots and roads.

West-facing beaches face the greatest risk, and the large swell could cause impacts as far south as San Diego County. Weather offices are advising that “everyone” should stay out of the water because of the hazardous surf.

“These are forecast to be EXTREMELY DANGEROUS conditions, as powerful waves and life-threatening rip currents pose an exceptional risk of ocean drowning and damage to coastal structures such as piers and jetties,” the National Weather Service in Oxnard, Calif., warned on Wednesday.