(CNN) A major California utility has temporarily turned off power for almost 60,000 customers because of fire threats.

Pacific Gas & Electric, based in San Francisco, announced the move because of elevated risks of fire weather -- a combination of strong winds, low humidity and dry conditions on the ground. The initiative is designed to prevent power lines from sparking fires.

Update: Public Safety Power Shutoff remains in effect for 17k customers in North Bay and 42k in Sierra Foothills. We continue to monitor the weather and will provide updates to our impacted customers in Napa, Lake, Sonoma, Amador, El Dorado and Calaveras counties. pic.twitter.com/Wqde9cqiQj — PG&E (@PGE4Me) October 15, 2018

The National Weather Service said a Red Flag Warning -- an alert that signals the potential of dire fire threat conditions -- continues through Monday morning for higher elevations of the North Bay and East Bay in northern California.

More than 22 million people are under Red Flag Warnings both in northern and southern California, CNN meteorologist Haley Brink said. An elevated risk of fire weather is forecast for northern areas and an extreme risk of fire weather has been posted for southern areas, including parts of Los Angeles and Ventura counties.

Sustained winds of 30 to 40 mph are possible Monday. Humidity below 15% is forecast, and wind gusts up to 70 mph are possible in the higher elevations, canyons and passes, Brink said.

Read More</s>Power lines remain deactivated in a dozen Northern California counties Monday morning, part of an effort by Pacific Gas and Electric to raise the odds against conditions conspiring to create a wildfire on par with last year’s Wine Country firestorm.

Making good on warnings issued Saturday, PG&E staff on Sunday night at about 8 p.m. deactivated the power lines to nearly 60,000 customers in Northern California. PG&E officials said they were relying on a combination of adverse conditions, including a National Weather Service-issued red flag warning, sustained winds above 25 miles per hour with gusts topping 45 mph, dry-fuel and live vegetation conditions, and field crews’ real-time observations.

As of Monday morning at 5 a.m., the power remained off in many Northern California counties, including Lake, Napa and Sonoma. The weather service said wind speeds have been decreasing since 3 a.m. Monday, a trend that will continue through mid-day. The red flag warning for the North and East Bay hills remains in effect through noon Monday, according to the weather service.

As of 8:03 PM, PG&E has proactively turned off power in extreme fire-risk areas of Lake, Napa and Sonoma counties based on localized weather forecasts calling for wind gusts of up to 50 mph tonight into Monday AM. Approx. 17,483 customers are impacted. https://t.co/Cr4Rqoc651 pic.twitter.com/kwJrMuRgI1 — PG&E (@PGE4Me) October 15, 2018

At 8:03 p.m., nearly 17,500 customers in three of those counties, Lake, Napa and Sonoma, lost power. Monday morning at 5 a.m., the power deactivation remained in effect.

In Napa County, about 5,800 customers in the towns of Angwin, Calistoga, Deer Park, Lake Berryessa, Napa, Pope Valley, Saint Helena were cut off, while Sonoma County saw unincorporated northeastern areas, and parts of Cloverdale, Geyserville, Healdsburg and Santa Rosa go dark. In Lake County, the towns of Clearlake, Clearlake Oaks, Clearlake Park, Cobb, Finley, Hidden Valley Lake, Kelseyville, Lakeport, Lower Lake and Middletown lost power.

Currently, PG&E power shutoffs planned for tonight do not impact customers within Santa Rosa city limits. Details: https://t.co/rBpZFlxTo1 pic.twitter.com/ozRrHDwJwz — City of Santa Rosa (@CityofSantaRosa) October 15, 2018

Given the Red Flag Warning that’s in effect, high winds in upper elevations of Sonoma County & the potential for extreme fire weather, additional firefighters (as seen here) from numerous fire departments across Sonoma County are on duty thru tomorrow (Monday) at noon. pic.twitter.com/QMHdM1SgEV — Santa Rosa Fire Department (@SantaRosaFire) October 15, 2018

An estimated total of 70,000 customers in the state were affected, including those in many communities in the Sierra Foothills counties of Butte, Sierra, Placer, Nevada, El Dorado, Amador, Plumas, Calaveras and Yuba.

As of 8:48 PM, PG&E has proactively turned off power in extreme fire-risk areas of El Dorado, Amador & Calaveras counties based on localized weather forecasts calling for wind gusts of up to 50 mph tonight into Mon. AM. Approx. 42k customers impacted. pic.twitter.com/I6OgAmfNlK — PG&E (@PGE4Me) October 15, 2018

In a statement Sunday. PG&E’s senior vice president of electric operations stressed the utility’s efforts to prevent another catastrophic conflagration.

“Nothing is more important than the safety of our customers and the communities we serve. We know how much our customers rely on electric service, and we have made the decision to turn off power as a last resort given the extreme fire danger conditions these communities are experiencing,” Hogan said.

“PG&E has a plan. We want our customers to have plans, too.”

After conditions hopefully ease Monday, PG&E crew members are expected to make any needed repairs to wind-damaged lines before restoring power, with most back online by Monday night or Tuesday at the latest.

Although the weather service’s Bay Area-focused Twitter account shared tweets saying peak winds in the North Bay hills topped out early Sunday evening around 50 mph, instruments atop Napa’s 4,300-foot Mt. St. Helena registered north winds at 60 mph with gusts up to 72 mph.

Peak wind speeds over the past 24 hrs. The two observations south of Middletown are located on Mt. St. Helena. Winds have been decreasing since about 3 am, a trend that will continue thru midday. A Red Flag Warning remains in effect for the N & E Bay Hills until Noon. #CAwx pic.twitter.com/OuUZTIVnWL — NWS Bay Area (@NWSBayArea) October 15, 2018

8 pm winds atop Mt. St. Helena (4300') near the Sonoma/Napa/Lake county line: North at 60 mph gusting to 72 mph. Winds elsewhere in the hills of the N and E Bay are gusting between 25 and 45 mph. Strong and gusty offshore winds will continue in the hills thru the night. #CAwx — NWS Bay Area (@NWSBayArea) October 15, 2018

Check back for updates.

Contact George Kelly at 408-859-5180.</s>The Latest: Utility shuts off power in California counties

SAN FRANCISCO (AP) — The Latest on Pacific Gas and Electric shutting off power to about 87,000 customers in parts of more than a dozen Northern California counties (all times local):

Pacific Gas and Electric says it will shut off power to about 87,000 customers in parts of more than a dozen Northern California counties.

The utility issued a statement Sunday evening saying the move was prompted by extreme fire weather conditions and strong winds.

Red flag fire warnings hit areas including 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.

The utility says most customers can expect power to be restored on Monday night.

Pat Hogan, senior vice president of electric operations, says: "Nothing is more important than the safety of our customers and the communities we serve. We know how much our customers rely on electric service, and we have made the decision to turn off power as a last resort given the extreme fire danger conditions these communities are experiencing."

Pacific Gas and Electric says it may shut off power in parts of more than a dozen Northern California counties.

The Los Angeles Times reports that the utility says the warning issued Saturday night was prompted by extreme fire weather conditions and strong winds expected Sunday.

Red flag fire warnings are expected in areas including 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.

PG&E said it could start turning off power Saturday night.

Gusty winds are expected Sunday in the hills of the Bay Area. Wind gusts in the higher elevations of the North Bay could reach as high as 50 mph.</s>SAN FRANCISCO — Northern California’s biggest utility has shut off power to tens of thousands of customers in an unprecedented step to prevent wildfires amid rising winds and official warnings of extreme fire danger.

Pacific Gas & Electric began turning off the lights in California’s wine country and other areas near the San Francisco Bay Area Sunday night. Schools in those areas cancelled Monday classes.

PG&E earlier announced its plan to shut power preemptively after authorities blamed its power lines for sparking some of California’s most destructive wildfires.

The utility faces payments of billions of dollars in damages and has sought to limit its wildfire liability in the courts and the state Legislature.

The National Weather Service forecast winds gusting to 45 mph (72 kph) on Monday in parched areas with drought-dried vegetation.</s>A utility company purposefully shut off electricity to nearly 60,000 Northern California customers Sunday night, aiming to reduce wildfire risks from power lines during extreme winds.

Pacific Gas and Electric planned to restore power to 70 percent of affected customers in the North Bay and Sierra Foothills late Monday night. As crews inspect lines for safety by helicopter, vehicles and on foot, the remainder will have power sometime Tuesday.

While it was the first time the company shut off power for public safety, PG&E announced its criteria and procedures for such an event in June, said spokesperson Paul Doherty. After wildfires devastated Northern California's wine country last October, he added, PG&E developed its community wildfire safety program division to make power grids and communities more resilient.

Two sagging PG&E power lines caused one of those wildfires during heavy winds, killing four people and injuring a firefighter, the California Department of Forestry and Fire Protection determined earlier this month. Trees or tree branches hitting PG&E power lines started another four wildfires in October 2017. Altogether, the power company has been blamed for igniting 13 wildfires last year.

"We're adapting our electric system our operating practices to improve safety and reliability," Doherty said of the safety program. "That's really the bottom line for us."

Turning off power to so many customers was 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. Conditions that led the company to shut off power included the National Weather Service's red flag fire warnings, humidity levels, sustained winds, temperature, dry fuel and local terrain, Doherty said.

The company de-energized more than 78 miles of transmission lines and more than 2,150 miles of distribution power lines Sunday night. Many schools in the area were closed Monday because of the planned power outage.

Late Saturday and early Sunday, PG&E warned 97,000 customers in 12 counties that the shut off might go into effect. Through automated calls, texts and emails, the company encouraged customers to have drinking water, canned food, flashlights, prescriptions and baby supplies on hand.

Power was also turned off in Southern California on Monday.

San Diego Gas & Electric turned off service to about 360 customers near Cleveland National Forest, where multiple fires have scorched large swaths of land in recent years.

SDG&E has pre-emptively shut off power to customers in the past, most recently in December when 14,000 customers went without power.

Southern California Edison, the primary electric provider across Southern California — including Los Angeles — has a similar power shutoff program. As of Monday night, SCE had yet to turn off power in any of its service areas, a spokesperson told USA TODAY.</s>SAN FRANCISCO (AP) — Pacific Gas and Electric says it may shut off power in parts of more than a dozen Northern California counties.

The Los Angeles Times reports that the utility says the warning issued Saturday night was prompted by extreme fire weather conditions and strong winds expected Sunday.

Red flag fire warnings are expected in areas including 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.

PG&E said it could start turning off power Saturday night.

Gusty winds are expected Sunday in the hills of the Bay Area. Wind gusts in the higher elevations of the North Bay could reach as high as 50 mph.</s>Pacific Gas and Electric purposefully shut off electricity to nearly 60,000 customers Sunday night, in fear that predicted wind speeds could fuel another wildfire in Northern California.

The "Public Safety Power Shutoff" remained in effect for 17,000 customers as of Monday morning. PG&E said customers could be potentially without power into Tuesday, until crews can visually inspect lines for safety.

The unprecedented move to turn off power to so many customers was a "last resort given the extreme fire danger conditions these communities are experiencing" said Pat Hogan, senior vice president of electric operations in a statement. Many schools in the area were closed Monday because of the voluntary power outage.

Saturday and early Sunday, PG&E warned customers in 12 counties that the shut off might go into effect. They encouraged customers to have drinking water, canned food, flashlights, prescriptions and baby supplies on hand.

This comes after officials announced earlier this month that two sagging PG&E power lines caused a Northern California wildfire that killed four people and injured a firefighter last year. The power company has been blamed for igniting 13 wildfires last year.

The Associated Press contributed to this report. Follow Ashley May on Twitter: @AshleyMayTweets</s>SAN FRANCISCO — Concerned about downed power lines sparking wildfires, two major California utilities took the rare step of cutting power to customers amid high winds — and another power provider was considering similar action.

Pacific Gas & Electric for the first time began cutting power Sunday night to tens of thousands of customers in Northern California after the National Weather Service warned of extreme fire danger across the state due to high winds, low humidity and dry vegetation.

San Diego Gas & Electric followed suit Monday, turning off power to about 360 customers in foothill areas near Cleveland National Forest, where multiple blazes have scorched large swaths of land in recent years.

SDG&E has pre-emptively shut off power to customers in the past, most recently in December when 14,000 customers went without power — many for four days.

Pacific Gas & Electric previously announced its plan to shut off power preemptively after authorities blamed its power lines for sparking some of California’s most destructive wildfires.

The utility expects to pay billions of dollars in wildfire damages and has sought ways to limit its liability through the courts and Legislature.

PG&E said about 87,000 customers had their power halted and more could be left in the dark depending on the weather. Some 60,000 customers remained without power. Schools in those affected areas canceled classes.

PG&E said it expected to restore power Monday night to most customers — though some residents won’t get electricity back until Tuesday.

“We know how much our customers rely on electric service, and we have made the decision to turn off power as a last resort given the extreme fire danger conditions these communities are experiencing,” PG&E spokesman Pat Hogan said.

PG&E said it began notifying affected customers on Saturday about possible outages. However, many said Monday they had received little or no notice.

Stewart Munnerlyn was scrambling to find generators to save $8,000 worth of ice cream at his creamery shop in Pine Grove, about 55 miles east of Sacramento. Munnerlyn said he is in Virginia visiting a sick relative and received three text messages Sunday night from PG&E saying it might cut power, but he didn’t know it actually happened until a friend called him.

“They knew what they were going to do obviously,” Munnerlyn said. “We weren’t given enough notice to properly prepare.”

Kevin Kathman, executive chef of wine country restaurant All Seasons in Calistoga, said $12,000 worth of food at the site would spoil if power isn’t restored soon.

Instead of tossing it, he was planning to cook over a fire during a block party for the “stressed out community” that includes winery owners in the middle of grape harvest. The power went out Sunday night and Calistoga remained without electricity Monday, even though Kathman said there was no wind.

“It’s a beautiful day,” he said. “We are all in disbelief that it’s not back on.”

PG&E spokeswoman Melissa Subottin said power was also cut to hospitals and other medical providers that are required to have backup power sources. PG&E officials visited 4,400 medical customers in the affected areas to personally warn them of the outages, she said.

The weather service predicted winds gusting to 55 mph in the Sierra foothills east of Sacramento. High winds were also expected in the state’s wine country north of San Francisco.

Southern California Edison said it was considering shutting off power to an undetermined number of customers. Strong wind gusts swept across the region with the arrival of the first fall Santa Ana winds — hot, sustained gusts that blow from the desert to the ocean.

A motorist in the Orange County city of Tustin was killed when a eucalyptus tree fell on her car in an apartment complex. The victim was 34. No further details were released.

Southern California Edison spokesman David Song said about 32,000 of its 5 million customers were experiencing power outages, but no shutdowns had been ordered by the utility. Song said Edison was investigating the cause of those outages.

Associated Press writers Jocelyn Gecker in San Francisco and Christopher Weber and John Antczak in Los Angeles contributed to this report.</s>FILE - In this Oct. 11, 2017 file photo, a Pacific Gas & Electric crew works at restoring power along the Old Redwood Highway in Santa Rosa, Calif. Northern California's biggest utility has taken the unprecedented step of cutting electricity for tens of thousands of customers in an attempt to prevent wildfires amid rising winds and official warnings on Monday, Oct. 15, 2018, of extreme fire danger. Pacific Gas & Electric began turning off the lights in California's wine country north of San Francisco and Sierra Nevada foothills east of Sacramento Sunday night. The utility said at least 87,000 customers had their power turned off and that more could be put in the dark depending on the weather. (AP Photo/Eric Risberg, File) (Eric Risberg)</s>FILE - In this Oct. 14, 2017, file photo, PG&E crews work on restoring power lines in a fire ravaged neighborhood in an aerial view in the aftermath of a wildfire in Santa Rosa, Calif. Northern California's biggest utility has taken the unprecedented step of cutting electricity for tens of thousands of customers in an attempt to prevent wildfires amid rising winds and official warnings on Monday, Oct. 15, 2018, of extreme fire danger. Pacific Gas & Electric began turning off the lights in California's wine country north of San Francisco and Sierra Nevada foothills east of Sacramento Sunday night. The utility said at least 87,000 customers had their power turned off and that more could be put in the dark depending on the weather. (AP Photo/Marcio Jose Sanchez, File) (AP)
The Pacific Gas and Electric Company, a major California utility based in San Francisco, announces they temporarily turned off power to 60,000 customers in 12 Northern California counties due to threats of wildfires. Red flag warnings are issued to 22 million people in the state.