Record-breaking hurricane activity in Pacific Ocean is battering SoCal

A season of tropical storms and hurricanes with record-breaking energy in the Pacific Ocean is battering the Southern California coastline.

Researchers at Colorado State University confirmed Monday that storms this summer have generated a higher level of accumulated cyclone energy than ever recorded, surpassing the prior seasonal record set in 2018. The metric is a measure of the total wind energy, intensity and duration of tropical storms and hurricanes.

“It’s been a wild season,” said Daniel Cayan, a climate researcher at the Scripps Institution of Oceanography at UC San Diego, noting that parts of Southern California‘s coast already have experienced significant damage ahead of any winter storms in store for the region amid the strongest El Niño on record.

The historic Long Beach boardwalk buckled after a barrage of storms over the last month. As Tropical Storm Rachel approached the coast over the weekend, powerful waves slammed into oceanfront homes, leaving some on the verge of collapse.

In Newport Beach, water from a massive swell — double the size that was initially predicted — blasted through 20-foot berms erected at the beach and inundated roads with about a foot of sea water ahead of Rachel’s arrival.

Elsewhere along the coast, the continuous battering from higher-than-normal ocean levels and strong waves this summer has washed away sand, profoundly altering the Wedge in Newport Beach, as well as beaches in San Onofre, Laguna Beach and San Clemente. The coastal damage has been so significant that Orange County declared an emergency last month.

The exceptionally active hurricane season in the Pacific is influenced by several factors including a long-term ocean heating trend caused by global warming, and higher nearshore ocean temperatures and a decrease in wind shear from El Niño, which can significantly weaken hurricane activity, UC Agriculture and Natural Resources climate scientist Daniel Swain explained during a recent webinar.

“El Niño in the Pacific Basin decreases wind shear, so it removes the inhibitive storm-decapitating effect of wind shear at the same time that it amplifies water temperature,” Swain said. “So it adds more fuel and it makes that fuel more likely to take advantage of its environment.”

Typically, once storms enter the cooler water in the eastern tropical Pacific, they weaken significantly. But the marine heat wave and El Niño conditions — bringing ocean temperatures 10 to 13 degrees higher than normal — have provided a more conducive environment for hurricanes such as Rachel to get close enough to affect the California coast.

These storms, combined with high tides and the Kelvin wave, which can add 6 to 12 inches to background sea levels, have resulted in significant damage and a reshaping of the coast over the summer.

And it’s not over yet, experts say.

Hurricane Simon, currently spinning along Mexico’s west coast, is expected to make landfall there this week, and forecasters say there’s roughly a 90% chance of another cyclone formation in the next seven days.

“I wouldn’t be surprised if we saw a couple more hurricanes or tropical systems forming in the Central Pacific, South Pacific area,” said Kristan Lund, a meteorologist with the National Weather Service in Oxnard.

Southern California also is bracing to see what El Niño has in store this winter.

The National Oceanic and Atmospheric Administration’s Climate Prediction Center said last week that there was virtually a 100% chance that the El Niño this season will be categorized as “very strong.” There’s also an 83% chance that this El Niño will be the strongest on record, going back to 1950, up from a 75% probability forecast last month.

Even if it doesn’t result in torrential rain, El Niño can wreak havoc on the coastline.

Beaches typically go through a seasonal cycle with powerful winter waves dragging sand out to sea and more mild summer waves depositing the sand back onshore. But El Niño winters generally bring even stronger waves, resulting in more sand loss and erosion.

“There’s likely to be pretty profound influences along the coast,” Cayan said of the months ahead. “There [are] also cliff failures and other impacts when you get these big waves that are higher and more active than normal, so there’s a lot of concern about that.”

Two of the strongest El Niños in the last 75 years, in 1982-83 and 1997-98, were associated with extensive damage to the Southern California coast, battering homes, flooding streets and damaging piers.

Another one — in 2015-16 — did not result in above-average rain but did cause record coastal erosion. During that winter, researchers determined that the more extreme waves were about 50% larger than usual and the level of beach erosion was 76% higher than normal.

“Since that really big winter in 1983, we’ve had several occasions of pretty active winter storms, but we’ve sort of dodged bullets because those storms, in general, didn’t fall upon the highest tides,” Cayan said. “So this winter, again, it’s going to be sort of a luck of the draw.”

This winter, if El Niño-fueled storms arrive during king tides, it’s likely that California will see significant coastal erosion, flooding and damage, Cayan said. King tides, which can push water levels past 7 feet, or higher during El Niño, are expected around Thanksgiving, Christmas and late January.

“Those periods are really critical for the fate of the California coastline and infrastructure this winter,” Cayan said.