'Bomb Cyclone' Drenches NorCal, Knocks Out Power For 66K

SAN FRANCISCO, CA — A destructive "bomb cyclone" storm triggered mudslides, sent people fleeing from their homes, shut down main thoroughfares, flooded apartment buildings and knocked out power for tens of thousands of Northern California residents over the weekend. First responders were scrambling to mitigate the damage wrought by the storm.

The National Weather Service’s Sacramento office warned of "potentially historic rain" ahead of the storm. The extreme "atmospheric river" system was forecast to effectively end another destructive wildfire season and quell some drought concerns in Northern California, but on Sunday it brought a slew of other dangers such as flooding and mudslide risks in fire-scarred California.

By Sunday morning, Mount Tamalpais just north of San Francisco had recorded a half-foot of rainfall during the previous 12 hours, according to the weather service.

"Some of our higher elevation locations could see 6, 7, 8 inches of rain before we’re all said and done," weather service meteorologist Sean Miller told The Associated Press.

Flash flood warnings were issued to several areas of Northern California, where fire-scarred land posed a significant risk of debris flows.

Flooding was reported across the San Francisco Bay Area, closing streets in Berkeley, inundating Oakland's Bay Bridge toll plaza and overflowing rivers in Napa and Sonoma counties.

Debris flows tend to manifest during massive rainfall events, transforming the ground into a treacherous river of mud. These mud rivers can flow rapidly, striking with little or no warning at avalanche speeds — faster than a person can run, according to Ready.gov, a website created by the U.S. government to help citizens cope with emergencies.

About 150 miles to the north, the California Highway Patrol closed a stretch of State Route 70 in Butte and Plumas counties because of multiple landslides within the massive Dixie fire burn scar.

“We have already had several collisions this morning for vehicles hydroplaning, numerous trees falling, and several roadways that are experiencing flooding,” the highway patrol's office in Oroville tweeted on Sunday. “If you can stay home and off the roads today, please do. If you are out on the roads, please use extreme caution.”

The extreme weather also toppled trees and tipped power poles, sending sparking wires into the roads.

Some 66,000 residents had lost power by 1 p.m., according to Pacific Gas & Electric. The utility warned ahead of the storm that the massive storm would likely bring torrential rain, heavy mountain snow and intense winds, which could cause widespread outages.

Also dubbed a "bomb cyclone," the powerful storm swirled violently over the state, and was expected to dump a foot of rain in some parts of Northern California and bring 8 feet of snow to the mountains, USA Today reported.

As the storm barreled through the Bay Area Sunday, PG&E was also warning residents not to touch or get anywhere near downed wires. Downed wires can be reported by calling 911 or PG&E directly at 800-743-5002.

"Never touch downed wires: If you see one, assume it is energized and extremely dangerous," PG&E tweeted on Sunday. "Do not touch or try to move it — keep children and animals away."

The North Bay remains hardest hit; as of 11:30 a.m., power was out to 43,319 customers, mostly in Marin and Sonoma counties, PG&E spokesman J.D. Guidi told Bay City News.

About 16,439 customers are affected on the Peninsula; 2,430 in San Francisco, 2,258 in the East Bay, and 1,582 in the South Bay.

PG&E started staging crews on Saturday to deal with the storm, with more 3,000 workers available to respond to outages, Guidi said.

See PG&E's outage map here.

On Sunday, emergency crews responded to flooded roads, downed wires and toppled trees all over the Bay Area on Sunday.

"Water levels are on the rise in many of our creeks right now due to the storm," the Santa Rosa Fire Department wrote on Twitter. The department posted video of rushing waters of a rain-swollen waterway at Flat Rock Park, at the confluence of Brush and Santa Rosa creeks. The waterbed was mostly dry just a week ago.

"Please stay away from the edges of these fast-moving waterways," department officials tweeted.

Several homes were flooded in Santa Rosa on Sunday and authorities were urging residents not to attempt to drive through flooded streets in the city.

There is currently flooding on Tachevah Dr. and Neotomas Ave. with water flooding homes in the area. Crews are on scene to address the impacts. As a reminder, please do not attempt to drive through flooded out roadways. Please be safe out there! pic.twitter.com/PNtwb0uQ7o
— Santa Rosa Fire Department (@SantaRosaFire) October 24, 2021

Evacuation warnings were issued for Santa Cruz and San Mateo counties on Sunday. In San Francisco, the threat of a large tree leaning in the city's Forest Hills neighborhood prompted fire officials to order the evacuation of three homes on Sunday morning, the San Francisco Fire Department said on social media about 11:10 a.m. Residents in the 2176-2178-2184 block of Ninth Avenue were being evacuated.

“If you are in the vicinity of a recent burn scar and haven’t already, prepare now for likely debris flows,” the Sacramento weather service tweeted. “If you are told to evacuate by local officials, or you feel threatened, do not hesitate to do so. If it is too late to evacuate, get to higher ground.”

Down south, parts of western Santa Barbara County saw evacuation warnings upgraded to orders in the area burned by the Alisal Fire, which ignited this month.

National Weather Service officials said the rains would persist into the night and were encouraging residents to stay home on Sunday and to avoid travel.

"It's a great day to stay home! Heavy rain across the area will lead to roadway flooding today into tonight," NWS officials in Sacramento tweeted. "Tonight into tomorrow night, snow will impact mountain travel. If you do have to drive, take it slow and leave plenty of time get to your destination."

Flash flood warnings were issued to several reaches of Northern California on Sunday, including where the destructive Dixie fire left a massive burn scar. Areas where fires impacted the topography become dangerous and ripe for "debris flows" during a storm such as this weekend's bomb cyclone, authorities warned.

READ MORE: What Are Debris Flows And How Can NorCal Residents Cope?

Ahead of the treacherous storm, Northern Californians were urged to charge cell phones and battery backups, and to tie down outdoor furniture and trash cans. Emergency kits or "go bags" should also be prepared ahead of the story, officials said.

The storm also prompted community leaders to cancel the Alameda County Fair, one of the most popular Bay Area attractions. Danville's bustling Fallfest was also canceled Sunday.

READ MORE:

• Alameda County Fair Canceled As 'Bomb Cyclone' Storm Hits
• Danville's Fallfest Canceled As Torrential Rains Arrive

We are getting reports of debris flows within the Dixie Burn Scar area especially impacting Highway 70 from Jarbo Gap to Greenville. #CAwx https://t.co/8yINGS46FH
— NWS Sacramento (@NWSSacramento) October 24, 2021

Californians celebrated when rain started falling earlier this week for the first time in any significant way since spring. The San Francisco International Airport set a record rainfall for Thursday, with 0.44 inches of rain tallied. The old record was 0.13 inches on the same day in 1970, the National Weather Service in the Bay Area tweeted.

Rain and snow will continue to drench central and Northern California before spreading into Southern California on Monday, although Southlanders woke up to a bit of drizzle on Saturday morning.

Incredible imagery of the bomb cyclone, with a pressure equivalent to a Category 4 hurricane (943 mb) driving an extreme atmospheric river into Northern California. #CAwx pic.twitter.com/UpN1DX34kh
— US StormWatch (@US_Stormwatch) October 24, 2021

The incoming heavy rainfall is welcome news in the Golden State, where exceptional drought conditions and another monstrous fire season has plagued residents and authorities working in treacherous burn zones.

"This rainfall is coming about a month ahead of average and will be very welcome in fighting the remaining fires, particularly in Northern California," according to Jon Porter, AccuWeather chief meteorologist. "Repeated storms delivering such copious rainfall will have a major effect on the wildfire season — effectively ending the wildfire season from Northern California northward."

Wildfires have ripped through 2.4 million acres in California this year, destroying or damaging more than 3,600 structures and killing three people, Cal Fire reported.

READ MORE:

NorCal Braces For 'Bomb Cyclone,' High Winds And Copious Rainfall

Danville Power Outage: 2,540 Affected In Massive Storm

Pleasanton Power Outage: 3,027 Customers Affected In Huge Storm

Evacuation Warnings Issued For Parts Of San Mateo County

The Associated Press, Bay City News and Patch Editor Kat Schuster contributed to this report.