Rain falls across California as thunderstorm threat grows. More storms forecast into weekend

Huntington Beach, CA - March 15: A walk with an umbrella amidst the rain at Bolsa Chica State Beach, which is partially closed after both sides of PCH were closed due to flooding between Warner Avenue and Seapoint Street in Huntington Beach Wednesday, March 15, 2023. Re-opening times were not announced. (Allen J. Schaben / Los Angeles Times)
Most areas of Southern California can expect up to half an inch of rain Wednesday, forecasters said. Above, people walk in Huntington Beach during a spring storm this year. (Allen J. Schaben / Los Angeles Times)

Rain moved into Southern California Wednesday as back-to-back storms dancing off the coastline are forecast to bring successive rounds of precipitation into the weekend, according to the National Weather Service.

Though widespread, intense rainfall is not expected, the rain across Los Angeles County could further exacerbate traffic issues as a portion of the 10 Freeway in downtown L.A. remains shut down after a fire last weekend.

Forecasters also warned Wednesday afternoon about a growing "instability" within the moisture-rich storm, which is increasing the threat for thunderstorms and high winds across Southern California, which could cause minor issues in the region.

“Brief heavy downpours, dangerous lightning” could accompany any thunderstorm, Ryan Kittell, a National Weather Service meteorologist in Oxnard, said in a briefing Wednesday. The storms Wednesday could also bring 30mph to 50 mph winds — the highest expected in the mountains and along the 5 Freeway — which could cause power outages and downed trees, he said. Brief bands of heavy rains could also cause some urban and creek flooding.

Read more: 10 Freeway closed: How to deal with the traffic nightmare in downtown L.A.

The chance of thunderstorms is most likely through Wednesday night in Southern California, Kittell said, but they remain possible through late Saturday, at the back-to-back storms' end. The region is facing an elevated risk for lightning through 4 a.m. Thursday, according to the National Weather Service.

Most areas in L.A. County can expect up to half an inch of rain Wednesday, but with further bands of rain expected, totals by late Saturday are expected anywhere from 1 to 3 inches, said Ariel Cohen, a meteorologist with the National Weather Service in Oxnard. He said the storm meteorologists had been tracking since last week had "kind of fragmented into parts."

A minor break in precipitation is expected Thursday before rainfall picks back up Friday and Saturday, forecasts show.

The second wave is expected to make landfall Friday and linger through Saturday, Cohen said.

Read more: Rain is coming to Southern California: How much and when?

Precipitation is expected across the Golden State as a "very elongated area of low pressure" moves along the California coast, Brian Garcia, a National Weather Service meteorologist in Monterey, said in a Tuesday briefing. The storms will bring "multiple rounds of rain" to California by the week's end, according to a weather service post on X.

In the Bay Area, precipitation is expected to pick up Wednesday afternoon and taper off until the next round comes in slightly stronger on Friday, said Roger Gass, a National Weather Service meteorologist in Monterey. Coastal areas in the region can expect 1 to 2 inches through Saturday, while the hills could see closer to 3 inches total.

Farther south in San Diego and Orange counties, rain totals will hover around 1 inch through the rest of the week, with some Southern California mountains getting slightly more. Thunderstorm pockets could also drive up those rainfall amounts.

The rainfall is expected to also make its way inland to the Central Valley, where forecasters are expecting rain and some snow beginning Wednesday night into Thursday, according to the National Weather Service. Rainfall in the valley region isn't expected to top 1 inch, but some of the Sierra's highest peaks could see over a foot of snowfall, with snow levels dropping to about 8,000 feet elevation.

Across Southern California's mountains, snow levels could drop this week as low as 7,500 feet — still above resort levels, Kittell said.

Read more: There's no drought anywhere in California: How long that's expected to last, and why

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This story originally appeared in Los Angeles Times.