Experts are predicting sea levels along the California coast could rise as much as a foot by the end of September as El Niño-warmed tropical water pushes a slow-moving wave up the coast of North America.
The swell moving up the coast is a planetary-scale process known as a Kelvin wave. It's triggered by changes in wind at the equator.
The wave originated along the equator. The surge will likely hit Cabo in late September and eventually hit Northern California in October. Experts report the Kelvin waves won't build on each other, but instead, sea level heights and temperatures will remain elevated for weeks, gradually subsiding before the next wave hits.
"So far this summer, what we've been seeing is that the actual water levels have been running about six inches above what the predicted water levels have been," Stefanie Sullivan, the lead meteorologist at the National Weather Service San Diego, said.
Sullivan told CBS 8 that the rising sea levels can bring hazardous conditions to the region.
"If we have our water levels already, at baseline, higher than what they normally are, then, especially with our King Tides around Thanksgiving and Christmas, or any high surf events, there's [a] higher potential that we could see coastal flooding. Especially in the places that already experience it, like Mission Beach and Oceanside. Those events could be either more frequent or, depending on the situation, possibly get a little further inland than they typically do," Sullivan said.
The Scripps Institution of Oceanography at UC San Diego shared that water temperatures along the California coast are expected to increase as the wave arrives, because it will weaken coastal upwelling, the process that brings cold, deep water to the ocean surface near California. That will further warm near-shore water that is already as much as 6 degrees above normal in Southern California.