Record-breaking rain soaks northwest California

An atmospheric river soaked northwest California on Monday into early Tuesday morning, delivering record-breaking rainfall amounts and dampening wildfires. 

Meteorologists are saying the system was unusually strong for an early-season storm. The heaviest rain was reported in Oregon and far Northern California, but light rain made its way down into the Sacramento Valley and the San Francisco Bay Area. 

“Typically, this is the type of storm that we’d see more so in November than September,” Jonathan Garner, a meteorologist with the National Weather Service’s Eureka office, said over the phone. “It’s a little early in the season for this type of rainfall event, but it’s not unheard of.”

Could this storm be an indication that California’s winter is going to be wet? “I don’t think that can be determined yet,” Garner said. “It could just be an anomalous event. It’s hard to say.”

In California, the heaviest rainfall was seen in an area that roughly stretches from Eureka to the California-Oregon border. Both Eureka and Crescent City broke same-day rainfall records for Sept. 25 by over a half-inch, the weather service said on social media. 

Eureka measured 1.56 inches; the previous record was 1.01 inches, measured in 1923. Crescent City saw an impressive 2.30 inches, surpassing its 1930 record of 1.11 inches. The King Range saw the highest totals, with a gauge on Cooskie Mountain recording 4.68 inches. 

The 2023 SRF Lightning Complex, which has delivered wildfire smoke to the Bay Area, received a soaking. Garner said the weather service doesn’t have access to a rain gauge in the fire area that straddles Del Norte and Humboldt counties, so exact totals aren’t available. He estimated a few inches fell based on the fact that Del Norte County generally recorded 2 to 4 inches and Humboldt County saw 1 to 2 inches.

“The rainfall is definitely moistening up the fuels in Humboldt and Del Norte counties where we saw the most rain,” he said. “That will reduce the wildfire risk.”

The Sacramento Valley saw only light showers, receiving traces of rain, while some locations in the foothills of the Sierra Nevada recorded a couple of tenths of an inch. The town of Paradise measures 0.25 inch. 

Jeffrey Wood, a meteorologist with the weather service’s Sacramento office, said, “Most of the heavy rain was contained to our north and our west.”

In the San Francisco Bay Area, the North Bay recorded the highest rainfall totals, and areas south of the Golden Gate saw only light sprinkles. Cazadero measured 0.54 inch, Occidental 0.51, Santa Rosa 0.16 inch of rain, San Francisco and Half Moon Bay 0.07, and Oakland 0.03.