Monster waves, some as tall as 30 to 50 feet, pounded Northern California's coast on Thursday, causing flooding, erosion and significant damage in the San Francisco Bay Area's seaside communities. The turbulent surf tore the "cement ship" from the pier at Seacliff State Beach in Aptos. Water spilled into the coastal hamlet of Capitola, and residents and businesses were evacuated. Waves crashed over the wall along Beach Boulevard in Pacifica.
National Weather Service forecaster Brian Garcia explained the so-called bomb cyclone that kicked up winds and dumped rain overnight is generating the high surf.
"All that wind on the backside on that area of the low pressure created all this wave energy, and it’s hitting our coast today, and it’s massive," Garcia said. "While we see the rain and the wind slowly start to abate, the impacts of that low pressure aren’t going to be done for another day or so because of that."
Garcia said the wave buoys miles off the shore of Point Reyes all the way down to Monterey were measuring waves up to 23 to 26 feet, at a dominant period of 18 seconds. Those waves grow as they reach shore. "What that means, in short, there’s a lot of water moving, with a lot of swell coming through," Garcia said. "We’re seeing surf in that 30-to-50-foot range on the coast. If you went out to Ocean Beach in San Francisco today, you would see some of the biggest surf you’ve seen in a while."
Some of the largest waves were at the famous offshore Mavericks break near Half Moon Bay.
The big swell arrived this morning at high tide and when strong southerly winds were blowing over the ocean and creating a storm surge, or an abnormal rise in the ocean waters, Garcia explained.
At the tidal gauge at Crissy Field in San Francisco, high tide this morning was predicted to hit 6.8 feet amid typical conditions, but with the storm surge, it rose to 7.7 feet. "We’re getting impacts in the bay like it’s a king tide," he said.
— Dani California (@DaniComifornia) January 5, 2023Water levels rose up and down the coast, and flooding occurred everywhere from Mill Valley and SF's Embarcadero to Pacifica and Santa Cruz.
"Any low-lying coastal areas will have ocean run-up that's farther up than usual — places like Jenner at the mouth of the Russian River, Muir Beach, Stinson Beach, Ocean Beach, Pacifica, Half Moon Bay," Garcia said.
The Bay Area's weather service has a high surf warning for local beaches in effect through 3 a.m. Friday. A flood warning was issued for most coastal areas of the region, including the bay shoreline, and is in effect through 4 p.m. Thursday, the weather service said.
Full Bay Area Storm Coverage
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