{"id":633174,"date":"2026-10-17T06:00:32","date_gmt":"2026-10-17T06:00:32","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/633174\/"},"modified":"2026-10-17T06:00:32","modified_gmt":"2026-10-17T06:00:32","slug":"el-nino-extreme-flooding-could-reach-all-time-high-this-christmas","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/633174\/","title":{"rendered":"El Ni\u00f1o extreme flooding could reach all-time high this Christmas"},"content":{"rendered":"\n

With homes nearly toppling into<\/a> the ocean and back-to-back floods<\/a> and hurricanes<\/a> amplifying our sense of dread, keeping track of all things El Ni\u00f1o can be overwhelming. <\/p>\n

So I called up Patrick Barnard, who spent years leading the U.S. Geological Survey\u2019s renowned coastal hazards team<\/a> in California and now helms key climate adaptation research at UC Santa Cruz<\/a>. A maestro at bringing together all manner of data, Barnard broke down the numbers in no-nonsense terms \u2014 explaining why the coming weeks and months might bring extreme flooding like we\u2019ve never seen before.<\/p>\n

\u201cAll the stars are aligning for a pretty dramatic winter,\u201d said Barnard, as he pored over the El Ni\u00f1o tea leaves, so to speak, and rattled off every high tide phenomenon on track to converge by the holidays. \u201cIf you start stacking all these things up, the flood risk just goes up exponentially.\u201d<\/p>\n

To start, the waters off the California coast have been the hottest they have ever been at this time of year. Multiple temperature records have been shattered, and an intense marine heat wave<\/a> has been churning since last December \u2014 making our typical high tides even higher \u2014 El Ni\u00f1o notwithstanding.<\/p>\n

Warm water, put simply, expands, whereas cold water takes up less space. And this heat wave alone, Barnard explained, has already made sea level rise temporarily by about 6 inches.<\/p>\n

Now add El Ni\u00f1o on top of these 6 inches. Historically, El Ni\u00f1o can raise water levels along the West Coast by an additional 6 to 12 inches throughout the winter, and key indicators for this season<\/a> are already pointing to a supercharged El Ni\u00f1o. <\/p>\n

(Think of El Ni\u00f1o as a reverse swing in global weather patterns that can make the ocean much hotter in parts of the world where it shouldn\u2019t be. This can turn cold places warm, unleash downpours in typically dry regions and throw other climate phenomena out of whack \u2014 like bringing hurricanes too close for comfort<\/a> in California.)<\/p>\n

So California is now facing possibly 18 inches, or 1.5 feet, of sea level rise, but we\u2019re not done yet: This winter also happens to be nearing the peak of both a 4.4-year high tide cycle and a lunar nodal cycle that occurs every 18.6 years, which will add a few more inches of sea level rise.<\/p>\n

\u201cIt basically adds about 2 to 4 inches on top of everything else \u2014 it doesn\u2019t sound like a lot, but 2 to 4 inches doubles the flood frequency in California,\u201d Barnard said, citing a pivotal global study that quantified how flood frequency changes with sea level rise<\/a>. \u201cSo that\u2019s another factor that\u2019s essentially doubling the flood risk. And with the heat wave, plus El Ni\u00f1o, plus the tides, think about how many times over you\u2019ve doubled it now.\u201d<\/p>\n

Then there\u2019s the Kelvin wave<\/a>, a massive, slow-moving bulge of water that essentially thickens the surface layer of the ocean and can add another 6 to 12 inches of sea level rise as it passes through. So double, perhaps quadruple, the flood risk again. Just this past week, a Kelvin wave proved to be quite the flood amplifier in Long Beach<\/a> and Newport Beach<\/a>, and scientists say there\u2019s another on the way. (A key factor in El Ni\u00f1o\u2019s development, Kelvin waves were first described<\/a> by Lord Kelvin, the same scientist who invented the Kelvin scale<\/a>, the international system of absolute temperature.) <\/p>\n

Add to all this the infamous king tide<\/a>, which usually brings dramatic flooding to California a few times each winter and can add another 12 inches, possibly more, to an already-high tide.<\/p>\n

These astronomical high tides are quite predictable, and as the orbits of the moon and sun and Earth would have it, three of the highest tides in recorded history are expected to hit California around Thanksgiving, Christmas and the week of Martin Luther King Jr. Day:<\/p>\n

Nov. 24 to 26, 2026Dec. 23 to 25, 2026Jan. 21 to 22, 2027<\/p>\n

What remains to be seen is whether a winter storm or another Kelvin wave will coincide with any of these three king tides.<\/p>\n

The wave-shattered homes and boardwalks<\/a> of this past week are a visceral glimpse into what a few additional feet of sea level rise could look like in California. To help visualize this further, consider the general rule of thumb that 1 foot of sea level rise could push the ocean inland as much as the length of a football field. Anything in the way of that shifting line in the sand \u2014 a seawall, a road or sand berm \u2014 would have to hold against the pressure of that much water trying to move in.<\/p>\n

After the last particularly intense El Ni\u00f1o, during the 2015-16 winter season, Barnard and a network of scientists assessed the damage along the West Coast and found that shoreline retreat \u2014 or how much the beach disappeared \u2014 was an eye-popping 76% higher than in a typical winter<\/a>. Researchers also found that wave energy was 50% higher, with some of the largest individual waves measuring more than 63 feet <\/a>off Mendocino and 55 feet off Point Reyes during a December 2015 storm.<\/p>\n

So at what point can we still call this an emergency if we know the water is coming? Coastal planners have been talking for years<\/a> about preparing for these existential challenges, and proponents of nature-based solutions<\/a> have been sounding the alarm on the need to revive our vanishing beaches and wetlands \u2014 the shoreline\u2019s original buffers from the sea. A law signed by Gov. Gavin Newsom<\/a> in 2023 requires every coastal city and county in California to develop a sea level rise plan by 2034, and more than a dozen key agencies have agreed<\/a> that California needs to prepare for at least 3.5 feet of sea level rise by 2050.<\/p>\n

All these higher-than-high tides might feel like inauspicious one-offs, but this El Ni\u00f1o season should be considered practice for the future. As Barnard puts it: \u201cThis is what it\u2019s going to look like every winter, in less than a generation.\u201d<\/p>\n

Barnard, whose research has been used by more than 200 government agencies across the West Coast and beyond, said he hopes this year\u2019s El Ni\u00f1o will shake people out of repeating the same knee-jerk reactions of building seawalls<\/a> and other increasingly futile defenses against the rising sea. Could communities instead shift into longer-term thinking about how to work with nature \u2014 and adapt with the realities of a changing landscape? <\/p>\n

\u201cIt\u2019s time to stop putting band-aids on things and just accept that these bigger flood events are going to be much more commonplace in the future,\u201d said Barnard, who now serves as research director at UC Santa Cruz\u2019s Center for Coastal Climate Resilience.<\/p>\n

\u201cAny preparations we take now, any kind of planning that we do for climate change \u2014 whether we\u2019re restoring dunes or restoring tidal marshes or getting out of the way \u2014 it\u2019s going to pay off immediately, as well as down the line. \u2026 It\u2019s really time to think long term about how we\u2019re going to manage our coast more effectively.\u201d<\/p>\n

More ocean news<\/p>\n

Alaska pollock, the fish behind imitation crab and America\u2019s fish sticks, is fueling a fight over trawling and bycatch. Annika Hammerschlag at the Associated Press<\/a> breaks down this controversy with the world\u2019s second-largest fishery.<\/p>\n

Also check out this big investigation from Ian Urbina<\/a> and The Outlaw Ocean Project, which goes deep into pollution, labor abuses and the hidden costs of seafood farms \u2014 and their role in depleting wild fish populations through the \u201cfishmeal\u201d being fed to farm-raised fish.<\/p>\n

Come talk sea level rise with me<\/p>\n

I\u2019m giving the keynote at the 2026 Bay Adapt Summit: Rising Together<\/a>, which takes place on Monday, Nov. 9, at the Exploratorium in San Francisco. It is an annual gathering of sea level rise adaptation practitioners and community members, and the panel discussions are open to the public.<\/p>\n

I will also be joining Malcolm Clemens Young, Dean of Grace Cathedral<\/a>, on Sunday, Nov. 8, for the Forum series, and the San Francisco Public Library<\/a> is hosting a book discussion of \u201cCalifornia Against the Sea<\/a>\u201d on Saturday, Dec. 5, as part of the library\u2019s One City One Book program. I will be in conversation with Marina Psaros, author of \u201cThe Atlas of Disappearing Places: Our Coasts and Oceans in the Climate Crisis<\/a>.\u201d<\/p>\n

One more thing<\/p>\n

The Marjorie Luke Theater in Santa Barbara will be doing a special screening<\/a> on Sunday, Oct. 25, of \u201cOut of Plain Sight<\/a>,\u201d the documentary I directed with Daniel Straub. The film is a cinematic expansion of my reporting on the legacy of DDT and toxic waste dumping<\/a> off the California coast, and I am grateful to see this story inspiring legislators in Congress<\/a> and resonating with audiences<\/a> across the world.<\/p>\n

The screening starts at 4 p.m., and I will be there for a post-screening discussion featuring scientists from UC Santa Barbara, Scripps Institution of Oceanography at UC San Diego, the Pacific Marine Mammal Center and San Diego State\u2019s School of Public Health.<\/p>\n

This is the latest edition of Boiling Point, a newsletter about climate change and the environment in the American West. Sign up here to get it in your inbox<\/a>.<\/p>\n

And be sure to tune in to the Boiling Point podcast<\/a>: In this week\u2019s episode, Times reporter Blanca Begert speaks with host Miranda Green about how the data center boom is driving immense pushback in California. Green also speaks with Cassie Buhler, a researcher at UC Berkeley who says there may already be an alternative to commercial AI that uses roughly 100 times less power.<\/p>\n

For more coastal and ocean stories, follow @rosanna.xia <\/a>and @outofplainsightfilm<\/a> on Instagram.<\/p>\n

More from Climate California <\/p>\n