A Northern California utility began shutting off power to tens of thousands of customers Sunday night and Southern California residents could face similar outages as powerful winds brought wildfire fears to the state after a year that saw record-high temperatures and scant rainfall.

Utility providers said planned outages were possible for up to 217,000 customers in more than a dozen counties as they brace for California’s first major red flag warning of the fall season. By Sunday night, the outages had affected about 59,000 customers in Lake, Napa, Sonoma, Amador, Calaveras and El Dorado counties.

The move is part of a strategy to reduce the risk of wildfires sparked by utility lines that break during extreme winds. Many of California’s most destructive fires — including several deadly blazes that raced through the wine country last year — were attributed to power lines.

“We are just watching the wind very closely,” said Andy Castagnola, a spokesman for Pacific Gas & Electric in Northern California. “We’ve let everybody know who would be impacted that we plan to do it so that they’re ready.”


PG&E warned about 70,000 customers in nine counties in the Sierra Foothills and 17,000 others in the North Bay about the potential for planned outages. After the extreme weather passes, crews are expected to inspect the lines to make any necessary repairs before restoring power, the utility said. Some outages could last until Tuesday.

In the Southland, Southern California Edison said it may shut off power in parts of Ventura, Los Angeles, Orange and San Bernardino counties and is identifying circuits in those areas that might be impacted by powerful Santa Ana winds. Up to 130,000 customers in 41 cities may be affected, utility spokesman Paul Netter said.

“We understand the impact [that] turning off power could have on customers,” Paul Grigaux, the utility’s incident commander, said in a statement. “We will only shut off the power as a last resort when weather conditions are so dangerous that flying branches, palm fronds and other vegetation pose a threat to power lines and the safety of the community.”

Gusts up to 60 to 65 mph were anticipated in mountain areas beginning late Sunday and peaking midday Monday, with possible isolated gusts near canyons as high as 75 mph, according to the National Weather Service in Oxnard.


Wind speeds of 25 to 40 mph were expected in the Santa Monica Mountains on Sunday, reaching about 30 to 45 mph by Monday, said Kathy Hoxsie, a meteorologist with the National Weather Service. Ventura County and L.A. County mountains saw stronger winds Sunday.

Hoxsie said even small sparks from mundane housework, such as hammering or putting up a chain-link fence, can cause a fire amid high winds.

“If you get sparks off of it, it can cause a fire,” she said. “We’re asking people to be very cautious using any outdoor tools.”

Drivers should be prepared for sudden, strong crosswinds on mountain roads, particularly near canyons that can cause a funnel of wind. Officials also warned that boaters and kayakers will be affected by strong winds in waters near the shore.


The winds were expected to continue into Tuesday morning.

In December, a series of wind-whipped fires destroyed homes from San Diego north to Sylmar, Bel-Air and into Ventura and Santa Barbara counties.

The worst of those, the Thomas fire, for a time became the largest wildfire in modern California history as it swept from Ventura to Montecito. It burned more than 280,000 acres and destroyed more than 1,000 structures.

Red flag fire warnings were in effect in such areas as the East Bay Hills in Oakland and Fremont, the hills of Napa and eastern Sonoma counties, the Diablo Range, the North Bay Mountains, the Sacramento Valley and the northern Sierra Nevada and Northern Coast Range.


“We have made the decision to turn off power as a last resort given the extreme fire danger conditions these communities are experiencing,” Pat Hogan, senior vice president of electric operations, said in a statement.

Gusty winds were forecast Sunday night of up to 70 mph in the North Bay mountains; up to 55 mph in the Sierra foothills; up to 50 mph in the East Bay Hills and Diablo Range; and up to 45 mph along the north coast.

“Critical fire weather conditions will continue in the North Bay Mountains and East Bay Hills through Monday morning due to a combination of strong, gusty offshore winds and low relative humidity,” the National Weather Service in Monterey said.

California’s largest utilities are spending huge sums to improve their power system to better withstand winds.


Southern California Edison is asking the state for permission to spend $582 million on improvements, including strengthening poles and using better technology to determine when winds put the power grid at risk.

victoria.kim@latimes.com

Twitter: @vicjkim

ron.lin@latimes.com


Twitter: @ronlin

alene.tchekmedyian@latimes.com

Twitter: @AleneTchek

UPDATES:


11 p.m.: This article was updated with additional power outages.

9:50 p.m.: This article was updated to reflect that the planned outages started in Northern California.

6:55 p.m.: This article was updated with information from Southern California Edison.

6:30 p.m.: This article was updated with more information from PG&E.


4:10 p.m.: This article was updated with a statement from Southern California Edison.

This article was originally published at 11:25 a.m.