The flooding and strong swells are already evidence of El Ni\u00f1o\u2019s powerful impacts, but the threats are likely just beginning. <\/p>\n
\u201cOur waters have been so far above normal \u2014 a foot to a foot and a half above what we would normally expect, because of the warm waters and because of Kelvin waves,\u201d said Robbie Munroe, meteorologist with the National Weather Service office in Oxnard.<\/p>\n
Kelvin waves are a key feature to the developing El Ni\u00f1o: They move warm water slowly for thousands of miles from the western Pacific Ocean toward the eastern Pacific, just off the coast of Peru. The warm water then hits the coast, eventually shuttling warmer ocean water to offshore California.<\/p>\n
Of all the risks El Ni\u00f1o poses to California, the risk of coastal flooding poses the highest level of certainty for later in the year, according to the weather service. Oceanic temperatures are continuing to rise in the part of the Pacific Ocean responsible for El Ni\u00f1o, and federal scientists say there\u2019s an 83% chance this El Ni\u00f1o will be the strongest in the modern record, which dates to 1950. <\/p>\n
The Kelvin waves are described as \u201ccoastally trapped\u201d as they must follow the coastline once they hit the coast of the Americas, with the shoreline to the right in the Northern Hemisphere. They don\u2019t crash on the shore, but they do raise ocean temperatures and raise the sea level, with their effects lasting for months before they eventually subside.<\/p>\n
Kelvin waves are thought to be a big contributor to the flooding.<\/p>\n
\u201cOceanic Kelvin waves are contributing to new\/broken water level records along the California coast, including some of the highest readings in over a century,\u201d the National Oceanic and Atmospheric Administration\u2019s National Ocean Service said in a statement<\/a>.<\/p>\n Two friends carefully high-step through a pond of sea water that floods Lido Park Drive where it meets Lafayette Avenue due to rising sea level in Newport Beach on Tuesday.<\/p>\n (Don Leach\/Daily Pilot)<\/p>\n The most recent first Kelvin wave arrived around the same time that swells from former Hurricane Rachel hit in early October, and sent seawater crashing into homes on the Long Beach Peninsula and covered Newport Beach\u2019s Balboa Peninsula with water.<\/p>\n It\u2019s now apparent that another Kelvin wave swept along the Southern California coast last week, and is contributing to sea levels, in some spots depending on the time of the day, having risen nearly 2 feet above what would ordinarily be expected from just astronomically influenced tides, according to North Carolina State University\u2019s Amaya. <\/p>\n The sea level rise being experienced now may be coming as quite a shock to some Californians, but in some ways, the sea level rise we\u2019re seeing has been a long time coming.<\/p>\n \u201cThe sea level rise signal has been a lot lower here than, let\u2019s say, on the East Coast or Gulf Coast,\u201d oceanographer Sweet said. \u201cThat said, when El Ni\u00f1os occur, like one is occurring now \u2014 the super El Ni\u00f1o \u2014 you can get three decades\u2019 worth of sea level rise in a month when these Kelvin waves come. It\u2019s not there forever, but when it\u2019s there, it\u201d can cause erosion and flooding.<\/p>\n On top of that, there\u2019s a good chance of large swells being whipped up by winter storms, said meteorologist Munroe, adding to the sea level. And while recently it\u2019s been south-facing beaches that are getting hit the hardest, swells will probably transition to coming from the northwest to the southwest, depending on the storms\u2019 orientation.<\/p>\n A big problem for California is that the coming king tides will be especially supersized. The astronomical tides will be among the highest considered possible for California, due to the arriving peaks of what are known as the 18.6-year lunar node tidal cycle and the 4.4-year lunar perigee tidal cycle, which arise from small changes in the orbit of the moon and affect tide-generating forces, according to Reinhard Flick, a researcher at the Scripps Institution of Oceanography at UC San Diego.<\/p>\n Over the course of a century, for instance, it\u2019s rare in La Jolla to see an astronomical high tide come in at 7 feet or higher above the baseline (which is currently defined as the average daily lowest-water level observed between 1983 and 2001), according to data provided by Flick. But that\u2019s set to happen on Nov. 25 (the day before Thanksgiving) and on Dec. 23, 24 and 25. And that prediction doesn\u2019t factor in higher-than-expected sea levels due to the hotter ocean.<\/p>\n By contrast, last week\u2019s tides weren\u2019t even king tides, UC Agriculture and Natural Resources climate scientist Daniel Swain said. They were higher than average, but they weren\u2019t the highest of the year, which is suggested when using the term \u201cking tides.\u201d <\/p>\n Last week\u2019s \u201crecord-breaking water levels … are not being caused by maximal sun and moon alignment, as is implied in \u2018king tide,\u2019 \u201d Swain said in an email. In fact, it\u2019s the \u201ccombination of only moderately high astronomical \u2014 sun and moon \u2014 high tides plus extraordinary\/record-breaking ocean level increases,\u201d fueled by the extreme marine heat wave and El Ni\u00f1o-fueled Kelvin waves. \u201cThat is, by far, the larger effect at present.\u201d <\/p>\n Scientists say this winter could be a preview of California\u2019s coastal future. Between 2000 and 2070, according to one estimate<\/a>, there could be more than 1 foot of additional sea level rise in L.A. under an intermediate scenario, and nearly 3 feet under a high scenario.<\/p>\n \u201cCalifornia has already experienced anywhere from 20 to 30 centimeters [8 to 12 inches] of background sea level rise. So this is just adding an additional foot on top of that,\u201d Amaya said of the more recent increases in sea levels. \u201cThis is just a warning shot from a warmer future. This is kind of our new reality.\u201d<\/p>\n![\"Two](\"https:\/\/www.newsbeep.com\/us-ca\/wp-content\/uploads\/2026\/11\/1793619250_142_.jpeg\")
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