California's Coastal Tide Gauges Are Breaking Records — and the Worst Is Still Ahead

Seawater broke tide records up and down the California coast on Monday and Tuesday, flooding streets, plazas and businesses from Newport Beach to San Francisco — and forecasters say the tides that arrive around Thanksgiving, Christmas and Martin Luther King Jr. Day will be higher still.

In Newport Beach, the tide gauge hit 8.4 feet on Tuesday, October 27, topping Monday's 8.3-foot reading that had itself already shattered prior records. The predicted tide for Tuesday was just 6.7 feet — meaning the water came in nearly 1.7 feet above what astronomical models alone would have produced, according to city spokesperson Georgia Rios.

In San Pedro, preliminary data from the National Oceanic and Atmospheric Administration's tide gauge showed 8.19 feet just after 9:45 a.m. Tuesday — surpassing Monday's preliminary record of 8.02 feet, which had already broken the previous all-time mark of 7.93 feet set in January 2005. NOAA's data at that station goes back to 1923, according to the National Weather Service.

Los Angeles Harbor recorded its highest tide ever on Monday, according to the National Weather Service. In San Francisco, the city saw its highest tide for the month of October, with two feet of inundation at high tide — significant, though still short of the city's all-time record of 2.82 feet set on January 27, 1983, also during a strong El Niño. In Los Angeles on Tuesday, the preliminary all-time record for 'mean higher high water' stood at 2.7 feet above the baseline.

What we're seeing right now is a precursor of the maximum tides expected this winter.— Karleisa Rogacheski, meteorologist, National Weather Service, Monterey

Three forces are converging to push water levels far above what tides alone would produce. El Niño has warmed Pacific waters significantly — ocean surface temperatures at Scripps Pier in La Jolla reached around 77 degrees in early August, against an average maximum of about 70, and were still around 73 degrees on Thursday against an average of 66 for this time of year, according to the Los Angeles Times. Those record-hot ocean temperatures are causing sea levels to run 1.25 to 1.8 feet higher than the moon, Earth and sun alignment alone would generate, scientists say. Layered on top is a once-every-20-years astronomical alignment in which the sun, moon and Earth line up to maximize gravitational pull on the oceans.

The coming king tides — the seasonal peaks Californians expect each winter — will be exceptionally extreme this year. According to Reinhard Flick, a researcher at the Scripps Institution of Oceanography at UC San Diego, the tides around Thanksgiving, Christmas and MLK Day will be amplified because they fall near the peaks of both the 18.6-year lunar node tidal cycle and the 4.4-year lunar perigee tidal cycle, which arise from small changes in the moon's orbit and affect tide-generating forces.

With the roughly two feet of extra water already measured this week from warm-ocean conditions, Newport Beach spokesperson Rios warned that the upcoming king tides — predicted to top 7 feet on their own — could reach nearly 9 feet, overtopping many of the city's seawalls.

We're expecting even higher ones from November and December.— Georgia Rios, spokesperson, City of Newport Beach

The National Weather Service issued a coastal flood warning through Thursday afternoon for Orange and San Diego counties, warning that 'low-lying property including homes, businesses, and some critical infrastructure will be inundated' and that 'some shoreline erosion will occur.' A coastal flood advisory covered Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties, where 'isolated damage of structures due to seawater inundation is possible to the most vulnerable areas,' according to the weather service.

In San Diego County, La Jolla's gauge hit 7.75 feet Monday — just below the station record of 7.81 feet set during the last 'very strong' El Niño on November 25, 2015, according to meteorologist Chandler Price of the National Weather Service in San Diego.

Communities scrambled to prepare. Newport Beach distributed roughly 25,000 sandbags over the weekend, and crews worked to pump out knee-high water and reinforce barriers along the Balboa Peninsula. Despite the flooding of streets and some businesses — including the Balboa Fun Zone — officials reported no significant widespread structural damage, which Rios attributed to residents heeding the city's warnings.

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 Francisco, the flooding was more spectacle than disaster — for now. Seawater pushed into a plaza along the city's eastern shore at lunchtime Monday, pooling around a large octopus statue and sending office workers scrambling when a departing ferry pushed additional water over the sidewalk and into a neighboring bike lane. Tony Massara, 72, rode a cable car from his Nob Hill home to photograph the scene, but said he was worried about the longer-term threat to the city's infrastructure and subway system.

It is a sight to see.— Tony Massara, San Francisco resident

Forecasters warn the greatest danger this winter will come if a major storm arrives at the same moment the king tides peak. Scientists say coastal flooding is expected to become increasingly worse through this year and into next year.

Why it matters — The records broken this week are a measurable preview of even higher king tides forecast for the holiday season, and scientists warn that a major storm arriving at the same time could push flooding well beyond what California's coastal infrastructure was built to handle.

Reported by ocregister.com, bostonglobe.com, latimes.com