S.F. Bay Area Storm Index: Third strongest storm since 1950 and strongest in 26 years

[Auggie]

San Francisco Chronicle / 10-25-21

The Bay Area’s third strongest storm since 1950 — and strongest in 26 years on the Bay Area Storm Index — slammed the region on Sunday, with drenching rain and powerful wind gusts expected continue pounding through Monday. While the “bomb cyclone” affecting parts of Northern California and the Pacific Northwest was not directly over the Bay Area, power outages, downed trees and localized flooding were widespread due to the Category 5 atmospheric river. Evacuation orders were issued in San Mateo and Santa Cruz counties due to debris flow danger in the CZU burn scar area, with flash flood and debris flow warnings in place for the Dixie and Caldor burn scars.

SNIP

The index is based on 24-hour rainfall at the official National Weather Service site in downtown San Francisco, the maximum sustained wind at San Francisco International Airport, and the highest wind gust at elevations below 1,500 feet in the nine Bay Area counties. According to Jan Null, , a meteorologist who runs Golden Gate Weather Services, the strongest storm since 1950 occurred on Dec. 12, 1995, rating 10 on the index. The second strongest, rating 9.8, was on Dec. 22, 1955. Sunday’s storm, rated 9.7, was tied for third place with two others, which occurred on Oct. 12, 1962, and Dec. 11, 1995.

SNIP

The North Bay received the brunt of Sunday’s rainfall, said National Weather Service meteorologist Brooke Bingaman. Rain gauges recorded 9.04 inches near St. Helena in Napa County, and 9.78 inches at Korbel Winery in Sonoma County. About 8.6 inches fell at Mount Barnabe west of Woodacre in West Marin. By Sunday evening, 3.77 inches of rain had dumped onto downtown San Francisco over 36 hours.

Link (paywall): https://www.sfchronicle.com/weather/article/S-F-Bay-Area-weather-live-updates-Track-the-16558095.php
Parallel coverage: https://www.sfgate.com

Also from the link: The Dixie Fire is (finally) 100% contained.