Cyclones to bring rain, renewed flood risk to California

Jan. 7, 2023 Updated 8:15 PM PT

Storm-weary California was getting little in the way of a reprieve this weekend, as the latest in a series of powerful winter storms trained its eye on the state.

In a bulletin published Saturday, the National Weather Service warned of a “relentless parade of cyclones” barreling out of the Pacific toward California, which was expected to intensify the risk of flooding in some parts of the state this week.

The first of five approaching atmospheric rivers — a stream of storms that will continue until about Jan. 19 — arrived this weekend. Heavy rain and mountain snow began late Friday night in Northern California and spread to Central California on Saturday, with some parts of the state expecting more than a foot of snow through early Sunday.

Satellite imagery of white areas over the western U.S.

The weather service’s Monterey office issued a flood watch advisory beginning at 4 p.m. Saturday and continuing through Tuesday for areas including San Francisco, Santa Clara, Monterey, Big Sur, the Carmel Valley, San Benito County, Pinnacles National Park, Los Padres National Forest and much of Central California.

Officials also warned of possible flooding of the Carmel and Salinas rivers in Monterey County; the Pajaro River in Santa Cruz County; the Russian River in Sonoma and Mendocino counties; the Navarro River in Mendocino County; the Eel River in Humboldt County; the Sacramento River in Tehama, Glenn and Butte counties; the Tuolumne River in Modesto; the Mokelumne and Cosumnes rivers in Sacramento County; and Bear Creek in Merced County.

In the Sacramento Valley, a weather system was expected to bring half an inch to 2 inches of rain, winds blowing up to 50 mph and potentially a thunderstorm before tapering off Sunday afternoon, said Katrina Hand, a meteorologist for the National Weather Service in Sacramento.

The deluge will continue, Michael Anderson, state climatologist for the Department of Water Resources, said in a briefing Saturday evening. “Monday and Tuesday is the second of five more storms and also the one that has our largest concerns right now,” Anderson said.

The “warmer, wetter and stronger” storm arriving Monday was forecast to dump 2 to 4 inches of rain on the Sacramento Valley and 3 to 7 inches on foothill and mountain areas, Hand said.

Hand said this system would be “particularly concerning,” as soils remain saturated and rivers and creeks overflowing from this week’s rainfall. The weather service has issued a flood watch for much of the interior Northern California area starting midnight Saturday and continuing through Wednesday afternoon, she said.

The Sierra will see heavy snowfall starting Saturday night, which, combined with strong southerly winds, could create “near-whiteout conditions” in the mountains, Hand said.

Rain was already falling Saturday afternoon in the Bay Area, which was forecast to get around an inch of rain before letting up Sunday morning, said David King, a meteorologist for the National Weather Service in the Bay Area.

The stronger storm system is expected to dump 2.5 inches of rain on the Bay Area starting Monday morning and even more at higher elevations, King said. The wettest areas will be the Santa Cruz Mountains, which could get 4 to 8 inches of rain, and the Santa Lucia Mountains, which might see anywhere from 5 inches to “up to 10 inches in extreme scenarios,” he said.

Such heavy rainfall carries the risk of flooding and power outages, as “everything is already saturated, both trees and the soil,” King said. At particular risk of overflowing are the Russian River in Sonoma County, the San Lorenzo River in Santa Cruz County and the Salinas River in Monterey County, all of which are expected to flood to some degree Monday.

King warned that flooding may remain a problem even after the rain stops. “There’s the influx of water, but then you have everything that trickles down from the mountains,” he said.

Another risk is that trees — dampened by rain and tenuously anchored in wet soil — could topple, knocking out power and even crushing people, King said, pointing to a fallen redwood in Occidental that killed a toddler Wednesday.

A woman was killed by a falling tree Saturday in Sacramento, the Sacramento Fire Department reported.

In Southern California, Saturday marked “really the last day of quiet weather for some time,” with clear skies and temperatures in the mid-60s, said Robbie Munroe, a meteorologist for the National Weather Service in Oxnard.

A powerful storm system is expected to move in starting Sunday night, bringing heavy showers and strong wind that could last through Wednesday, Munroe said. Another “more widespread, stronger storm” is predicted to descend on the region next weekend, he added.

Oncoming storms are expected to bring 1 to 2 inches of rain to coastal areas Monday and dump heavy snow in the Sierra.

Munroe said this upcoming storm system will bring “at least that much rain, if not more” as the one that rocked California earlier this week, causing flooding and mudslides, toppling trees and knocking out power to homes. Rivers and creeks, already swollen by earlier storms, overflowed their banks.

In Carmel, a 50-foot wave coursed through a home, submerging it in waist-deep water, smashing out windows and carrying off an attached deck, said Capt. Curtis Rhodes of the California Department of Forestry and Fire Protection’s San Benito-Monterey Unit.

“I’ve been here for 17 years, and I’ve never seen anything like it,” Rhodes said.

Although the family that lived in the house was able to escape, six people throughout the state were killed in the storms, including three whose bodies were found in or around their cars after a levee gave way near Sacramento and the toddler killed by a toppled tree in Sonoma County.

Times staff writer Matt Hamilton contributed to this report.