Maps show how much precipitation California measured amid thunderstorms

UCLA climatologist Daniel Swain reported on Twitter that storms in northern California were “wetter than expected” and that isolated areas saw wet precipitation ranging from 0.10 inch to 0.30 inch.

“This will reduce the number of new fires,” Swain wrote. “Bad news: Record vegetation will still allow for ‘lingering’ fires that will appear in the coming days.”

Measurable rains were reported in San Francisco on Friday morning, with the downtown gauge registering 0.01 inches at 5 a.m. This is the first time the city has seen rain in September since 2019, and the first time it has seen rain on September 10 specifically since 1978, the National Weather Service noted.

San Francisco 0.01 “of rain at 5 a.m. It has been a long time since it rained at the official downtown gauge specifically on September 10; the last time was in 1978 with 0, 08 “. For any day in September, the last time there was measurable rain in SF was 0.03 “on the 27th in 2019.

– NWS Bay Area (@NWSBayArea) September 10, 2021

The highest totals in the bay area were at one gauge at the top of Cummings Peak between Martinez and Hercules, and another at Moraga; both recorded 0.09 inches of rain, the weather service said.

“It wasn’t a lot of rain,” said Cory Mueller, a weather service forecaster. “But usually with these systems we never expect too much rain, but really any rain is nice to have, especially where you have those lightning. Even our highest amounts have stayed below a tenth of a. inch in the bay area. It’s not what we would call a pouring rain. But when we’re so late in the season, it’s all good. “

Measurable rains fell on the two largest wildfires in the state, the Caldor fire near Lake Tahoe and the Dixie fire in the southern Cascades and northern Sierra Nevada. The precipitation on the Caldor fire was more significant.

“Light rains are currently falling over the entire eastern half of #CaldorFire. Lightning continues throughout the area,” Jericho Island, a Twitter account providing updates on the wildfires, share Friday morning.

A weather gauge in Strawberry, a community along Highway 50 that was threatened by the Caldor fire, showed 0.29 inches of measurable rain. At a Kirkwood gauge, 0.15 inch was recorded.

“It’s definitely along I-80 that we’ve seen the highest totals,” Mueller said, noting the rain that fell north of the Caldor fire. “Blue Canyon saw a little over three-quarters of an inch. Going down towards Caldor’s fire it goes from a few hundredths in the lower elevations to almost four-tenths in some areas. They did quite well on one part. Caldor’s Fire. But I wouldn’t say it was widespread. “

As of Friday morning, the impact of rain and lightning on the Caldor blaze was unclear, but Cal Fire is expected to provide an update later today.

Rain gauges are rare in the Dixie Fire area, but the few there have shown very light rain.

“As they walked towards the Dixie Fire, they saw a little less, usually around a quarter of an inch, some areas around a few hundredths,” Mueller said.

The nearly 2-month-old Dixie Fire came back to life on Thursday as the cold front descending from the Pacific Northwest raised winds, triggering new evacuations and threatening communities of Hat Creek and Old Station.

The thunderstorms brought heavy thunder and lightning, and PG&E reported more than 1,200 cloud-to-ground strikes in northern and central California. There have been new starts of fire, and Cal Fire should have more information on that later this morning.

As the storms continue to push east and out of our region, we have decided to end the red flag warning.#CAwx pic.twitter.com/vQVw0i3hAd

– NWS Bay Area (@NWSBayArea) September 10, 2021

In the Bay Area, Roger Gass of the Weather Service said before sunrise that storms were abating in the North Bay and moving across the East Bay. But, he said, “The threat is starting to abate.”

The risk of thunderstorm activity continued in northeastern California on Friday morning, the weather service said.