San Pedro tide gauge shatters 100-year record as Southern California flooding spreads up the coast

A tide gauge at San Pedro recorded 8.02 feet Monday morning — the highest reading since measurements began there in November 1923, surpassing the previous record of 7.93 feet set on January 10, 2005. And forecasters say the worst may still be ahead: even higher tides are expected Tuesday, with the potential to shatter additional century-old records up and down the Southern California coast.

Floodwaters from Newport Harbor had already spilled onto Balboa Peninsula streets and into businesses at the Balboa Fun Zone before Monday's high tide even reached its crest. Residents of Long Beach saw inundation along Bayshore Beach, Naples and the Peninsula. The Guardian reported that in the Marin County town of Mill Valley, video showed paddleboarders gliding past cars that were stranded on a submerged road.

Newport Beach bore the brunt of Monday's surge. The city recorded a high of 8.3 feet — nearly two feet above what the tide alone would produce — and a tide of 8.5 feet is forecast for Tuesday morning at 9:50 a.m., according to the Newport Beach Police Department. Potential levels could reach 8.5 feet again Wednesday at 10:28 a.m. City crews were pumping out knee-high water and reinforcing sandbags along the harbor side of the Peninsula even as the tide was still running.

We saw about 25,000 sandbags go this weekend. We really saw the community come out. So I think a lot of the success of not having immense amount of flooding damage is due to residents taking part and grabbing sandbags for their homes.— Georgia Rios, spokesperson, City of Newport Beach

In San Diego County, La Jolla recorded a sea level of 7.75 feet Monday — just below its all-time record of 7.81 feet, set during the last very strong El Niño on November 25, 2015. With higher tides forecast for Tuesday, that record is also at risk, according to the National Weather Service.

That's very close to the record at the station, which is 7.81 feet. At this rate, considering we're expecting higher tides tomorrow, we could break it.— Chandler Price, meteorologist, National Weather Service San Diego

The National Weather Service has issued a coastal flood warning through 1 p.m. Thursday for the entire Orange County coastline and for San Diego County, warning that low-lying homes, businesses and critical infrastructure will be inundated and some shoreline erosion will occur. A coastal flood advisory — covering a wider but less severe risk — extends through the same period for Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties, where tides as high as 8 feet are possible. In the Bay Area, officials warned of up to 2.1 feet of inundation in low-lying coastal areas.

Three overlapping forces are driving the extreme water levels. El Niño and a Kelvin wave have already pushed ocean levels 15 to 22 inches above normal in the region, according to Newport Beach city manager Seimone Jurjis. Record-hot ocean temperatures — the surface at Scripps Pier in La Jolla reached around 77 degrees in early August, against an average maximum of about 70 — are causing seawater to expand, adding another 1.25 to 1.8 feet above what astronomical tides alone would produce, according to scientists cited by the LA Times. The tides are also converging near the simultaneous peaks of two lunar cycles — the 18.6-year lunar node tidal cycle and the 4.4-year lunar perigee tidal cycle — a combination rooted in minor shifts in the moon's orbit, Reinhard Flick, a researcher at the Scripps Institution of Oceanography at UC San Diego, said.

A foot and a half may not sound like much, but in a coastal community like ours, it can mean the difference between water staying below a seawall and water spilling into streets, garages and homes, especially during some of the highest tides of the year.— Seimone Jurjis, city manager, Newport Beach

The flooding has already disrupted transportation beyond the roads. Orange County Line service on Metrolink was halted Monday on the stretch between the Laguna Niguel/Mission Viejo and Oceanside stations, with trains running only as far as Laguna Niguel/Mission Viejo through Friday, according to iHeart. To help residents relocate vehicles from areas at risk of flooding, Newport Beach lifted parking enforcement through Wednesday evening.

Newport Beach had declared a local emergency more than a week before the tides arrived, giving crews time to reinforce beach berms, install sandbags and deploy water pumps. Orange County Board of Supervisors Vice Chair Katrina Foley said additional sandbags were being arranged for Laguna Hills ahead of Tuesday's expected peak.

The city has built up a giant berm and the county has been working with the city to distribute sandbags. Yesterday, we got a request for more sandbags, so I put that request in and we are prepared to provide extra sandbags for Laguna Hills tomorrow night.— Katrina Foley, Vice Chair, Orange County Board of Supervisors

The NWS office in San Diego urged residents to avoid beaches during high tides, stay well back from the water's edge, and keep off rock walls and jetties. Officials also warned against driving through flooded roads without knowing the water's depth.

This week's tides are not the last threat on the calendar. Scientists warn that even higher king tides are expected around Thanksgiving, Christmas and Martin Luther King Jr. Day — and if significant storms coincide with those events, the flooding risk will be substantially worse. The NWS also flagged a potentially moderate to strong storm system that could bring rain to Southern California over Halloween weekend, with high confidence of rainfall Saturday and Sunday, though timing and intensity remain uncertain.

Why it matters — A rare convergence of El Niño-elevated seas, record-hot ocean temperatures and a once-in-two-decades lunar alignment is pushing California tides to levels not seen in a century — and scientists say even more extreme flooding is coming around the major holidays this winter.

Reported by theguardian.com, latimes.com, kfiam640.iheart.com, cbsnews.com, yahoo.com