While meteorologists on Sunday morning were still predicting large, but not record-breaking rain totals, a storm system rolled in off the Pacific and pummeled the Bay Area with way more rain than most of us were expecting, causing flooded roads, neighborhoods, and more.
It seems to be a story that fits with the climate-change narratives about extreme weather that defies historical precedent. And Sunday's "bomb cyclone" and atmospheric river event, centered off the Pacific around the Alaska and and Pacific Northwestern coast, looked a lot more like the Category 3 and 4 hurricanes that we've watched from afar drenching the South and the eastern seaboard. In the end, it was being called a Category 5 atmospheric river.
Certainly one of the largest & strongest west coast cyclones I can recall! For its location (20-40N/120-140W) it set the new minimum sea-level pressure (942.5 hPa w/ 10 kt winds).— Philippe Papin (@pppapin) October 24, 2021
Its huge wind/rain footprint affecting the NPAC from British Columbia to California. #BCStorm #CAwx pic.twitter.com/Qumd9LreUR
Truly amazing satellite imagery of the powerful storm (technically a "bomb cyclone," as some have noted, due to its very rapid strengthening) affecting nearly the entire West Coast Sunday afternoon. What an incredible specimen of a textbook mid-latitude cyclone! #CAwx #ORwx #WAwx pic.twitter.com/7xgIcxfRaZ— Daniel Swain (@Weather_West) October 24, 2021
While meteorologists had predicted that the North Bay and San Francisco would see the heaviest rains earlier in the day Sunday, the weather system actually moved slower toward the south than predicted, leading to more steady rainfall accumulation and a somewhat different storm trajectory Sunday than originally predicted.
This resulted in flooding across most Bay Area counties — and flooding that was not relegated to just extremely low-lying areas. Also, parts of San Francisco, including I-280 where it crosses Mission Street, experienced flooding.
KUMX 8 PM PDT radar update - it is still raining.— NWS Bay Area (@NWSBayArea) October 25, 2021
This system is moving slooooowly. southward. Continued rain can be expected in the #BayArea with the heavier stuff approaching the Monterey Peninsula later tonight.#CAwx #CArain #AtmosphericRiver pic.twitter.com/clnysimEFJ
Marin County is experiencing heavy flooding as a powerful atmospheric river slams a majority of Northern California. The storm is expected to bring 3 to 7 inches of much needed rain. #storm #AtmosphericRiver #drought pic.twitter.com/qTQyWCpoPf— Justin Sullivan (@sullyfoto) October 24, 2021
In Santa Rosa cars are being pulled out of ditches tonight. Rachel Hallin just sent me this video from outside her home. Stay safe out there! https://t.co/WVDb1QE7vW @abc7newsbayarea pic.twitter.com/9f08At7rEZ— J.R. Stone (@jrstonelive) October 25, 2021
The storm that came to drench Northern California on Sunday continues to break records, and we'll likely still be tallying the numbers well into Monday and Tuesday. But here are are a few:
- The San Francisco-based Golden Gate Weather Services, which maintains the Bay Area Storm Index, said Sunday that this was the strongest storm to hit the Bay Area in 26 years. Also, it was the third-strongest storm in terms of rainfall to hit the region since 1950.
- The area of low pressure on the Pacific Coast that helped create the atmospheric river is being called the deepest in decades.
- Just after noon on Sunday, a wind gust was recorded at SFO at 60 miles per hour.
- The Russian River in Sonoma County, running at extremely low levels all summer, went from a level of less than 6 feet to over 12 feet at 2 p.m. on Sunday, per the Santa Rosa Press Democrat.
The low pressure off the Pacific Northwest coast is the most intense/deepest in decades. It's bringing hurricane force wind gusts to the PNW coastline and much needed, albeit flooding, rains to California. pic.twitter.com/XXAACGjJBZ— Delé Balogun ⛈ (@hurricanejourn) October 24, 2021
Meteorologist Daniel Swain pointed back to his own 2018 article that predicted that more extreme precipitation events like this one were likely to hit the California coast due to climate change — and here, in October, well ahead of the traditional "rainy season", we have one.
In San Francisco, small floods formed throughout the city, including this one in the Outer Richmond that was being battled by residents with brooms.
Flooding 31st and California AVOID AREA pic.twitter.com/orvzHAGovM— SAN FRANCISCO FIRE DEPARTMENT MEDIA (@SFFDPIO) October 25, 2021
Also, the Embarcadero flooded in SF — as did many roadways — as the Bay was overtopping the seawall.
Marina Blvd is closed due to flooding and bay is overtopping Embarcadero. All city depts are coordinating on resiliency planning, but no funding plan yet to protect coastal infrastructure pic.twitter.com/kgLzfXntd7— Jeffrey Tumlin 🏳️🌈 (@jeffreytumlin) October 24, 2021
Please avoid non-essential travel. Crews have been out along the Embarcadero clearing drains but still more rain expected and possible flooding. @SFFDPIO @SF_emergency @sfpublicworks @MySFPUC pic.twitter.com/SJla9vtI0T— Port of SF (@SFPort) October 25, 2021
Climate scientists have continued to try to tell the globe that extreme, unseasonable events likes these are likely to become the norm, even if we still see them as new and abnormal. And parts of the Bay Area are now going through the whiplash of a very tense fire season that gave way to record-setting rain, flooding, mudslides, and a historic and fire-season-ending storm.
It's a lot to take. But welcome to the 2020s.