Atmospheric River Pummels Napa Valley; More Rain Coming

NAPA VALLEY, CA — Napa Valley and the Bay Area were battening down the hatches as a severe storm caused by an atmospheric river slammed the region. The storm brought widespread flooding, thunder, lightning, power outages and winds of up to 60 mph in higher terrains.

As of Tuesday afternoon, the worst of the storm appeared to have passed, at least for the day. The National Weather Service downgraded the storm from a “Level 3” to a “Level 1” on the Storm Impact Scale, and at around 12:30 p.m. the National Weather Service began canceling flood advisories that were issued throughout most of the area early Tuesday morning.

In Napa Valley, the weather was 56 degrees and cloudy as of 4:30 p.m., following nearly 2 inches of rain in 24 hours, according to the National Oceanic and Atmospheric Administration. Winds of 14 mph were reported Tuesday, though gusts could swell to 47 mph. AccuWeather reported a 40 percent chance of thunderstorms.

Rain is expected to start up again Wednesday night, and continue through New Year’s Eve.

On Saturday, 0.73 inches of rain is predicted in Napa, and wind gusts could reach up to 37 mph. The first day of 2023 is forecast to be partly sunny and 60 degrees, but even more rain is predicted all of next week.

The NWS said Monday that its latest five and seven-day forecasts signal what could be the wettest end of the year in the Bay Area and northern Central Coast since 2005. The largest rain totals have been reported in the North Bay.

By early Tuesday, the National Weather Service reported that Mt. Tamalpais had already received 4.10 inches of rain. As of 4 p.m. Tuesday, Kentfield reported a 24-hour total of 4.65 inches, Venado reported 4.90 inches, Mt. Veeder reported 4.02 inches, Napa Corporate Yard reported 3.03 inches, St. Helena reported 3.36 inches, Santa Rosa reported 2.94 inches, Napa Airport reported 1.85 inches and Mill Valley reported 2.56 inches, according to the National Oceanic and Atmospheric Administration.

Just south of the Golden Gate Bridge, San Francisco recorded 1.86 inches; Oakland recorded 2.41 inches, and San Jose International Airport recorded 0.68 inches. Further south along the coast, Ben Lomond recorded 4.46 inches, and Soquel recorded 3.11 inches.

SFO Airport reported gusts as high as 47 mph, and gusts of up to 60 mph were reported in higher terrains.

The storm left widespread flooding and chaos in its wake. PG&E said that 6,800 customers across the Bay Area reported power outages by 9 a.m. Tuesday. Flooding was reported near Santa Rosa, Napa, Redwood City, and Oakland, as well as on the 101, I-580, and on Highway 1 in San Mateo County, in addition to many other incidents. The California Highway Patrol said it was responding to more than 60 incidents on Bay Area freeways Tuesday morning, and BART trains were delayed by up to 20 minutes.

Early Tuesday morning, intense rain in the East Bay caused the roof of a Big 5 Sporting Goods store to collapse. No one was injured, but surrounding stores are closed as officials inspect their structural integrity.

Do you have stories or photos from the rain? Email maggie.fusek@patch.com.