By Soumya Karlamangla, California Today, Writer

What an El Niño winter could mean for California. Plus, Interstate 10 in Los Angeles fully reopens today.

More than 150 inches of snow was reported in areas in California from snowstorms last winter.Philip Cheung for The New York Times

Odds are that this winter’s going to be a wet one.

The intermittent climate phenomenon known as El Niño, which typically means more rain and snow for California, developed over the summer and is expected to intensify in the next few months. And this year’s El Niño is predicted to be an exceptionally strong one — maybe even ranking in the top five on record, according to Daniel Swain, a climate scientist at U.C.L.A.

“This is likely to become an event that is historically significant,” Swain told reporters earlier this month. “All of California has elevated odds of a wetter-than-average winter.”
Of course, there are no guarantees. Experts emphasize that not every El Niño period is extra wet in the Golden State, and that the effects of the weather pattern often vary across the state (typically, El Niño’s effects are greater in dry Southern California than in the north).

“We’ve had wet years in California that are not El Niño, like last year,” Alex Hall, the director of the Center for Climate Science at U.C.L.A, told me. “And we’ve had dry years when El Niños are occurring.”
Even so, the deck is stacked in a soggy direction. Between 50 and 70 percent of El Niños since 1950 have led to above-average winter precipitation in California, according to the National Weather Service — meaning that we could be in for a second consecutive rainy winter.

Because of a torrent of atmospheric-river storms that slammed California last winter, the state received 141 percent of its average annual rainfall in the 12 months ended Sept. 30, according to state data. The period ranked as California’s 10th wettest water year since record-keeping began 128 years ago.

Hall told me that California could benefit from another wet winter, which would help return moisture to soil that was parched by years of extreme drought. A year ago, all of the state was experiencing drought conditions; now the figure is less than 5 percent.


“At a minimum, we need an average year,” he said. “It would be nice to get an average year, to keep us feeling very resilient.”
The state won’t be able to capture as much of the rainfall and snowmelt as it did last year, because reservoirs are already much fuller than they were a year ago. This month, Gov. Gavin Newsom fast-tracked a plan to build a new state reservoir — the first in nearly half a century — but it won’t be ready for some time.

State officials say they’re preparing flood control infrastructure and watching for risks. Experts say that if the winter is rainy, the danger of flooding will be even greater than it was last year, when levee breaches wreaked serious damage on communities in California.
“There is a lot of flood risk throughout the state,” Gary Lippner, deputy director for flood management and dam safety at the California Department of Water Resources, told reporters last month. He noted that California’s coast in particular did not have extensive flood control systems. “That keeps me awake a little bit at night, going into an El Niño year,” he said.

And before you go, some good news

The California grizzly bear, one of the state’s most recognizable symbols, is getting a new, slightly lesser-known companion: the pallid bat.
Under a new State Senate bill that Gov. Gavin Newsom signed in October, the pallid bat will become the state’s official bat, joining the California State Library’s list of state symbols in 2024.

Light golden in color and typically around three to five inches in length once full grown, pallid bats are most commonly found in the western parts of North America and have been known to live in habitats from the desert and the Sierra Nevada to the coastline. The state legislators who wrote the bill chose them because, as a natural pest predator, the bats protect the state’s agriculture.
West Coast dwellers through and through, the pig-snouted bats are also known for their immunity to scorpion venom and for their social nature. “Other than being messy, they’re a great bat to have around,” Corky Quirk of NorCal Bats, a bat rescue organization, told The Sacramento Bee.