Coastal Care – Illuminating the science • celebrating our coasts • empowering communities

Excerpt:
The abnormally strong event may boost extreme weather, flooding and erosion of the coast.

Few states are more sensitive to what’s happening in the Pacific Ocean than California — and what’s happening in the Pacific this year has no modern precedent.

Because of that, California is expected to face a much higher risk than normal for powerful, moisture-laden storms late this fall and winter, especially from December onward, driven in part by a record-breaking El Niño that resulted in a statewide emergency declaration last month.

“We have built right to the edge. The most valuable property is on the sand,” said Gary Griggs, a coastal scientist and professor at the University of California at Santa Cruz. “This winter in particular, I think it’s going to show what these communities are up against.”

California is no stranger to weather extremes. Over the last 130 years, two California water years stand above the rest: 1982-83 and 1997-98. Both coincided with super El Niño events, similar to the one unfolding now.

El Niño is a natural warming of the tropical Pacific Ocean that occurs every two to seven years.

This year’s strong event is anything but typical — and it could have serious consequences across the United States, spanning places like beach towns and the Sierra Nevada mountains.

Communities along the shore are preparing for an El Niño-fueled “coastally trapped wave” — a bulge in the ocean surface that is expected to raise California’s sea levels by up to a foot in October.

The trapped wave, on its own, is not destructive, experts said. It won’t come crashing onto the beach like a tsunami.

But the higher sea levels it brings could become damaging when combined with high tides and storms.

This week, Hurricane Rachel, despite tracking almost 1,000 miles away from Southern California, could cause minor coastal flooding, beach erosion and dangerous rip currents. Tides of up to seven feet are predicted in coastal parts of Orange and San Diego Counties, where an alert is in effect.

The combination of elevated sea levels and high tides could become especially important this winter. If an extra-high “king tide” coincides with a coastal storm, the effects could compound and be severe.

Here’s when these highest tides are expected: Nov. 24-26, 2026, Dec. 22-25, 2026, Jan. 20-23, 2027

“We’re already seeing the high tides, the tall surf, to the point where the surfers are elated along our coast,” said Warren Ontiveros, deputy director for the department of beaches and harbors at Los Angeles County. “They’re having field days.”

But “those waves also cause damage,” he emphasized. “They cause erosion…”