Bomb Cyclone and ‘Atmospheric River’ Pummel California – The New York Times
Two storms converged in the Bay Area on Sunday, bringing floods, high winds and some much-needed rain to a drought-stricken state.
Send any friend a story
As a subscriber, you have 10 gift articles to give each month. Anyone can read what you share.
[radio sounds and static] Tree down into a house.
Neil Vigdor and
California braced for winter storms and flash floods on Monday as meteorologists warned of a “bomb cyclone” and an “atmospheric river,” a convergence of storms that unleashed heavy rain to parts of the Bay Area, along with high winds, flash floods and the potential for heavy snow in the Sierra Nevada.
From Marin County to the area just south of Big Sur along the Pacific Coast, flash flood watches were in effect until late Sunday night and, in some areas, early Monday morning, including parts of the San Francisco Peninsula. The system was so vast that it was expected to reach southern British Columbia on Monday, where it was set to bring rain and strong winds, according to the National Weather Service in Seattle and Tacoma, Wash.
The National Weather Service issued a winter weather warning on Monday with heavy snow in the Sierra Nevada through Tuesday morning.
Here’s a look at a few SR areas impacted by the storm. Thanks to residents for reporting many critical issues, and THANK YOU to our hard-working city crews & public safety personnel who responded all day! Storm info: https://t.co/LQetAF3l4b pic.twitter.com/rwmHAWSmT7
The convergence of storms comes at a challenging time for California, which has been besieged by wildfires and drought, the result of extreme weather brought on by climate change.
The state authorities warned that areas with burn scars, where vegetation was at least partially eliminated by a fire, could see debris flows of rushing mud, rocks or vegetation that may sound, as they phrased it, like a freight train.
The California Governor’s Office of Emergency Services said on Twitter early Sunday that it was monitoring burn scars in Kern, Santa Cruz and El Dorado Counties.
The warnings continued through Monday, replacing the problems of too much fire with too much water in some parts of the region.
Crews were focusing on hot spots as they finished off their firefighting work on the 16,970-acre Alisal Fire, northwest of Santa Barbara, which was about 97 percent contained on Monday morning, said Veronica Garza, a U.S. Forest Service spokeswoman.
The concern has shifted to the potential for flooding, she said.
After heavy rainfall in Santa Barbara County on Monday, emergency management authorities told residents to shelter in place and go to inner rooms or higher floors because of life-threatening flash flooding and debris flows in the Alisal Fire burn area.
Gina DePinto, the spokeswoman for the county, said the shelter-in-place order mostly pertained to the Gaviota coast northwest of Santa Barbara, and the ranches that use Refugio Road, which stretches from the coast into the canyon. Residents had been urged on Sunday to evacuate, the sheriff’s department said.
“We can’t force people to leave,” Ms. DePinto said.
“Excessive rainfall” over El Dorado County’s burn scar, which was caused by the Caldor fire, could cause life-threatening flash floods, the National Weather Service in Sacramento said on Monday.
Parts of Fresno and Madera counties were also given flash flood warnings on Monday as heavy rainfall made the ground susceptible to slides in the Creek Burn scar area, the Weather Service said.
On Monday, about 100,000 customers were without power in California, according to PowerOutage.US, a site that tracks outages.
Pacific Gas & Electric said on Monday morning that most of the customers still without power were on the San Francisco peninsula and in Marin and Sonoma Counties.
Though Oregon and Washington hadn’t seen significant rainfall from the storm, strong winds were to blame for at least two deaths near Seattle, where a tree fell on a car. About 38,000 customers were without power in Washington on Monday morning, PowerOutage.US reported.
A few thousand customers in Oregon were without power as well.
Parts of Washington experienced strong wind gusts, including Everett, about 25 miles north of Seattle, where gusts of up to 61 m.p.h. were recorded, according to the National Weather Service in Seattle.
“The atmospheric river is aiming a fire hose, if you will, into our area,” Sean Miller, a meteorologist for the Weather Service in Monterey, Calif., the forecast office for the Bay Area, said on Sunday.
An atmospheric river is a concentrated plume of moisture that extends over the ocean, typically in the troposphere, the lowest layer of the atmosphere, Mr. Miller said. The current trough was angled toward the North Bay, he said.
In the Pacific Northwest, a bomb cyclone, a type of storm known for its falling atmospheric pressure, was expected to push the atmospheric river south, affecting areas south of San Francisco, Mr. Miller said.
“This is more typical of something we tend to see in December or January,” he said, pointing out that the confluence of the two meteorological phenomena was “anomalous.”
Throughout the day, the San Francisco Fire Department posted updates on Twitter about flooding, felled trees, fires, and stalled vehicles on flooded roadways. On Monday the department said it rescued two adults who had become trapped in a car after driving into water along Hunters Point Expressway. One of them received medical care.
In Santa Rosa, about 55 miles north of San Francisco, roadways in parts of the city looked like streams. The city’s fire department said several creeks and streets were flooding, and urged residents to avoid travel. The department also shared video of a mudslide on Twitter that had developed in a burn scar area from the Grass Fire, which was active for 23 days until it was fully contained on Oct. 20.
The deluge wasn’t limited to the Bay Area, as landslides and dangerous road conditions were reported in areas across Northern California.
In Placer County, Interstate 80 was closed in both directions near the Nevada state line as heavy snow fell, the California Highway patrol said on Monday morning. A winter weather warning was in effect through the night, the weather service said.
In Truckee, north of Lake Tahoe, the highway patrol said on Twitter on Sunday afternoon that rocks and water had fallen down a mountainside, blocking a road.
On Tuesday, Gov. Gavin Newsom issued a proclamation extending California’s drought emergency statewide and asked residents to redouble their water conservation efforts. This has been California’s second driest year on record, with near-record low storage in the state’s largest reservoirs, the governor’s office said.
Severe drought conditions, worsened by climate change, continue to affect much of the Western United States and even the northern part of the Great Plains.
While droughts are not uncommon in the region, scientists say that climate change, in the form of warming temperatures and shifts in precipitation, is making the situation worse.
Several large wildfires are currently burning in California, including the Dixie fire, the second-largest in state history, which has burned more than 963,000 acres, destroyed 1,300 buildings and killed one firefighter, according to a New York Times wildfire tracker.
Since the start of the year, wildfires across the West have burned more than six million acres.
Christine Hauser, Jesus Jiménez and Derrick Bryson Taylor contributed reporting.