{"id":841103,"date":"2026-09-08T23:16:10","date_gmt":"2026-09-08T23:16:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/841103\/"},"modified":"2026-09-08T23:16:10","modified_gmt":"2026-09-08T23:16:10","slug":"sudden-sea-level-rise-tied-to-el-nino-is-about-to-hit-the-california-coast","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/841103\/","title":{"rendered":"Sudden sea level rise \u2014 tied to El Ni\u00f1o \u2014 is about to hit the California coast"},"content":{"rendered":"

A version of this story appeared in the CNN Weather newsletter. To get it in your inbox, sign up for free here<\/a>.<\/p>\n

The sea level along California’s coast will increase by about a foot by mid-October due to the influence of El Ni\u00f1o<\/a>, which is driving a large volume of water northward from offshore of Mexico and Central America.<\/p>\n

This water is coming in the form of a coastal “Kelvin wave<\/a>,” and it will mark the arrival of one of the first significant impacts of the powerhouse El Ni\u00f1o<\/a> taking shape in the tropical Pacific. According to Dillon Amaya, an oceanographer at North Carolina State University, the wave is a clear signal that El Ni\u00f1o has arrived in California.<\/p>\n

“Typically, we think of El Ni\u00f1o and its impact on precipitation, but some of the first indications that El Ni\u00f1o is really occurring are the arrival of these coastally trapped waves,” he said.<\/p>\n

\ud83c\udf0a Follow the CNN Weather app for the latest El Ni\u00f1o impacts<\/a>.<\/p>\n

A coastal Kelvin wave is not one that a person typically sees at a beach, breaking and crashing. Instead, it’s barely perceptible to the human eye as it slithers northward from offshore of Mexico’s Baja Peninsula at about six miles per hour. It is detectable, however, using satellites that measure changes in ocean heights.<\/p>\n

You can’t surf a Kelvin wave, but it does affect surfing<\/a>. These waves are important because of their role in raising coastal sea levels, which increases the likelihood of damage from astronomical high tides and winter storms that are also affected by El Ni\u00f1o, scientists say. In essence, one El Ni\u00f1o-related phenomenon \u2014 sea level rise \u2014 is compounding the damage caused by others.<\/p>\n

Kelvin waves in the open ocean are massive, slow-moving and slosh up and down, like water in a bathtub<\/a>. Once they hit land, Kelvin waves can shift direction, moving north and south, parallel to the coast \u2014 raising ocean levels by 6 to 12 inches as they go.<\/p>\n

The ongoing El Ni\u00f1o, which is characterized by much hotter-than-average sea-surface temperatures in the tropical Pacific, is forecast to be the strongest such event<\/a> on record since at least 1950. El Ni\u00f1o temporarily increases water levels on top of long-term rising sea levels from human-caused climate change.<\/p>\n

Water levels along the California coastline have already been increasing in other ways tied to El Ni\u00f1o, Amaya said, including an earlier coastal Kelvin wave that reached California in May and June. The elevated sea levels that will result from the upcoming wave will further raise water levels and put the state at greater risk of coastal flooding, he said.<\/p>\n

These large, undulating Kelvin waves are actually part of what helps El Ni\u00f1o form, transporting heat from the western Pacific Ocean to its central and eastern regions, near the equator. These waves help push huge quantities of ocean heat under the sea surface, in a process known as downwelling. When they reach the central and eastern tropical Pacific, the undersea ocean heat rises, or upwells, increasing ocean temperatures there.<\/p>\n

In about 120 days, a Kelvin wave can travel from the western Pacific to the Pacific Northwest coastline of the US, or even as far as the Gulf of Alaska, raising ocean heights as it goes.<\/p>\n

“It’s an epic transit,” Amaya said.<\/p>\n

In addition, sea levels are also increasing along the West Coast because the hotter waters associated with El Ni\u00f1o are expanding to take up more space.<\/p>\n

“The wave would add to what is already there,” Amaya said. The total sea level height, including this latest wave, is anticipated to be 10-to-14 inches higher than normal along the California coast, he said.<\/p>\n

\"The<\/p>\n

The sun rises on Hurricane Lowell as it tracks near Hawaii on the morning September 7, 2026. Besides raising sea levels along California’s coast, El Ni\u00f1o also increases the likelihood of hurricanes in the Pacific that send their own waves towards California. – CIRA\/CSU & NOAA<\/p>\n

Patrick Barnard, research director at the Center for Coastal Climate Resilience at the University of California, Santa Cruz, said the ocean height increase puts many coastal residents at risk of flooding.<\/p>\n

“Because so many of our communities are built right at sea level on the West Coast, and our extreme water levels don’t vary widely, every 2 to 4 inches of sea level doubles our flood risk,” Barnard said.<\/p>\n

Amaya noted that the background sea level rise since the preindustrial era along parts of the California coast has been about one foot, so these El Ni\u00f1o-related changes will double that century-long trend all at once, albeit temporarily.<\/p>\n

“El Ni\u00f1o has arrived. This is some of the first evidence that El Ni\u00f1o is impacting the United States.”<\/p>\n

For more CNN news and newsletters create an account at CNN.com<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"A version of this story appeared in the CNN Weather newsletter. To get it in your inbox, sign…\n","protected":false},"author":2,"featured_media":841104,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[2356,33123,257089,58629,192,271487,79,125661,32359,50629],"class_list":["post-841103","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-california","tag-california-coast","tag-dillon-amaya","tag-el-nino","tag-environment","tag-kelvin-wave","tag-science","tag-sea-level","tag-sea-level-rise","tag-water-levels"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/841103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=841103"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/841103\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/841104"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=841103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=841103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=841103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}