A fierce and persistent storm 800 miles off the California coast is continuing to churn water to dangerous levels across the Pacific Ocean – generating surf that will ease on Christmas Day but return to dangerous heights on Thursday through the weekend.
Dry skies are predicted on Wednesday following a turbulent storm that pounded the coast with massive waves on Monday and Tuesday. But some rain will return on Wednesday night, especially along the coast and North Bay, according to National Weather Service meteorologist Roger Gass.
“The same storm system that’s been producing the rain over the last five or six days is continuing to spin off ripples, little spurts of moisture,” said Jan Null of Golden Gate Weather Services.
A distant low pressure system, stalled far off the coast, is creating the perfect ingredients for big swells: sustained high winds, prolonged periods between waves and a long “fetch,” when the wind blows over vast distances of water.
The northwest waves normally come in 10-second intervals. Recent Bay Area waves are now arriving about once every 20 seconds; in Half Moon Bay on Tuesday, the period was as long as 26 seconds. “The longer the period, the more energy you have,” said Null.
“Every beach looked out of control, like it could not hold the waves,” said surf photographer Jack Bober, who went to Mavericks and San Francisco’s Ocean Beach on Monday and Tuesday. “There were waves breaking every kind of everywhere. The energy was like nothing I had ever felt before. There was so much power.”
The waves caused three recent tragedies on beaches in the Watsonville and Monterey regions. One man died at Sunset State Beach after being trapped beneath debris. A second was swept from rocks on 17 Mile Drive in Pebble Beach, where he had reportedly climbed to take a photo. Another man is missing and presumed drowned from Marina State Beach, where he was swept by a large wave. Bystanders attempted to save him but were unsuccessful, according to Sgt. Chris Johnson of the Marina Police Department.
The region’s major wharfs — in Capitola, Santa Cruz and Pacifica — remain closed. Extreme waves on Monday destroyed the end of the Santa Cruz Wharf. Based on an initial observation, there has been no additional damage to the Capitola wharf, which was badly damaged in a 2023 storm, after Tuesday’s storm, said Capitola police captain Mike Kilroy. Pacifica Pier was badly damaged in last year’s storms.
Waves of up to 20 feet — formidable “triple overheads” that are three times higher than a surfer — were reported Tuesday along California’s central coast from Santa Cruz’s Steamer Lane to San Francisco’s Ocean Beach on Tuesday, thrilling surfers and creating hazardous conditions for unwary beachcombers, according to the National Weather Service.
While the waves were smaller than Monday’s surf, a high surf warning remained in effect. The Weather Service advised people to stay away from the water’s edge and watch for waves.
But by Wednesday, weather experts said that the threat was likely to be downgraded to a high surf advisory. Wind should recede.
The big rollers are created by a low pressure system that is stalled off California’s northwest coast. When a low pressure system from the north collides with high pressure systems from the south, the differential generates strong, fast winds.
Winds in the Gulf right now are measuring a punishing 60 miles per hour — nearly hurricane force.
The rotating energy of this gyre is transferred to the ocean, where waves blow over miles, piling up into mammoth swells.
A channel on the Pacific Ocean floor magnifies these waves, which can reach up to 50 feet high.
That’s why winter is the time for big-wave surf. On Monday and Tuesday, surfers faced giant mountains of moving water at Mavericks, an iconic surf spot a half mile offshore in San Mateo County.
The same storm generated waves big enough to hold Hawaii’s Eddie Aikau Big Wave Invitational, a celebration of Hawaiian culture and a test of human bravery, for just the eleventh time since its founding in 1984. Surfers caught waves as tall as 50 feet high, exceeding the height of three-story buildings.
Winner Landon McNamara, a North Shore local, knifed his way down a wave’s flank and emerged victorious with arms raised high. “The entire ocean landed on his shoulders, and he still came out successful,” one announcer declared.
Pounded by three years of rough surf, the Bay Area’s historic wharfs are struggling. They were constructed of old timber piles that are submerged 20 feet in the sand and bedrock, according to Jessica Kahn, public works director for the city of Capitola.
The wharfs are damaged by uplift, she said. “When the waves in a big swell come under the wharf, they lift up the boards of the decking, which pulls up all those other structural elements,” she said.
In addition, “big debris can batter the piers, and that causes damage, as well,” she said.
The region’s old wooden wharfs and piers are being replaced by fiberglass piles with high-density polyethylene “sleeves,” an enclosure that protects the piling from marine growth, abrasion and damage, she said. The polyethylene also creates greater resiliency against uplift.
In the Sierra, the series of storms will move very fast from Thursday through the weekend, with little break between each one, according to Palisades ski resort.
Sunny skies, light winds, and highs in the 30s will prevail on Christmas Day. A weak and warm storm will arrive for Thursday, with another on Friday and yet more over the weekend.
“Last year, we didn’t really have snow until the middle of January,” he said. “So it’s been a good start.”
Snow levels are expected to be all over the place, varying with each storm. It will snow as low as 6,000 feet on Thursday morning, but could rain as high as 8,500 feet by Friday morning. It will also be warm on Saturday.
“A lot of people were predicting a Christmas miracle,” said professional skier Andy Hays of Olympic Valley, who skied the steep KT-22 run on Tuesday, where six inches of snow fell. “I’m not sure it’s that. One turn is really good, and the next two turns are less good. But the snow is definitely helping.”