LOS ANGELES — Southern California Edison officials said electric circuits in some high fire-risk areas might be shut off Sunday night or Monday, as the first big Santa Ana windstorm of the fall will bring wind gusts of up to 75 miles per hour to the area.

A spokesman for SCE said neighborhoods in foothill communities from Santa Clarita to Pasadena and in San Bernardino County could get their electricity shut off, under a new state policy that allows protective blackouts. Santiago Canyon and nearby foothill areas in Orange County might also see pre-emptive blackouts, but not Malibu or the Santa Monica Mountains, where winds were not expected to exceed SCE’s danger thresholds.

We are monitoring weather conditions near you and are ready to respond. Due to high winds, we are exploring the possibility of a proactive power shutoff to limited parts of your community. No power has been shut off at this time and you will be notified if any action is taken. — SCE (@SCE) October 14, 2018

At midafternoon Sunday, spokesman Paul Netter told City News Service that certain mountain-adjacent neighborhoods in Los Angeles, Orange, Ventura and San Bernardino counties have been notified there is a “possibility of a shutdown of power” in some limited areas because of high winds.

🚩 Red Flag Warning in effect beginning 3 am Mon. 🚩 / Winds will peak Mon. with gusts to 60 mph and remain strong thru Tues. 🌬️ / Min. humidity 5-10% / Any fires that start will have extreme fire behavior 🔥 / Please exercise caution outdoors #OneLessSpark #cawx pic.twitter.com/r4m1LGOVnW — NWS San Diego (@NWSSanDiego) October 15, 2018

“I want to emphasize that no decision has been made regarding power shutdowns,” Netter said.

Edison is acting under new authority from the California Public Utilities Commission, which okayed shutdowns before fires break out. Such unprecedented blackouts are allowed because of the years of drought and changing weather patterns, CPUC safety experts have said.

#FireWeatherWatch in multiple counties in Southern CA upgraded to #RedFlagWarning Monday morning through Tuesday night due to strong Santa Ana winds and low humidity. Take steps now to be ready to “Go” in the event of an evacuation. Learn more: https://t.co/hHTBtHlGh9 pic.twitter.com/kQGpSXHqD1 — CAL FIRE (@CAL_FIRE) October 15, 2018

Neighborhoods that might see intentional blackouts Sunday night or Monday include Newhall, Stevenson Ranch, Castaic, Santa Clarita, Valencia and Canyon Country in northern L.A. County; and the swath of foothill neighborhoods from Newhall Pass east to San Bernardino County, including San Fernando, Sylmar, La Canada-Flintridge, La Crescenta, Montrose, Pasadena, Glendora, Azusa and Covina.

San Bernardino County communities on the list include parts of Fontana, Rancho Cucamonga, Alta Loma, San Bernardino, Mt. Baldy, Lytle Creek, Upland and Rialto.

The Los Angeles Department of Water and Power services much of the Los Angeles area, and is not part of the intentional blackout warnings.

In Orange County, neighborhoods in parts of Orange, Irvine and Rancho Santa Margarita were in potential blackout zones, as well as back country in Silverado and Trabuco Canyons.

Red Flag warnings were posted to go up at 10 p.m. Sunday night in western Los Angeles and Ventura counties Sunday night, and forecasters said the approaching weather pattern was predicted to be a bit more severe than earlier thought.

Portions of Riverside County were also identified as high-risk zones for wildfires, but SCE did not list the region as a candidate for preemptive power outages, Netter said. He said that could change, but wetter conditions in southeastern parts of Southern California and a confluence of other factors reduced the risk there.

“Even though it is in the Red Flag area, Riverside County hasn’t met our threshold for precautionary shutdowns,” said Netter.

Meanwhile, Riverside Public Utilities, the agency that supplies power in the city of Riverside, does not plan on implementing public safety outages, according to assistant general manager George Hansen.

He said his utility’s above-ground lines pass over urban areas, making them less likely to spark a wildfire than SCE’s infrastructure, some of which runs over wooded, mountainous terrain. However, Hansen added that local crews would be on standby in case any sort of emergency occurs.

San Diego Gas and Electric Co. officials said they were not planning blackouts.

Gusty and potentially damaging Santa Ana winds were predicted to arise Sunday night and Monday morning, NWS officials said. Gusts between 60 and 75 mph were held possible through Monday.

A significant warming and drying trend will develop as a high-pressure system over inland deserts pushes air through canyons and over mountain slopes, the forecast said. High temperatures in 80s to lower 90s will be prevalent along the Los Angeles coast and valley areas.

But overnight lows will be quite chilly in some wind-sheltered areas and the interior valleys. A Freeze Watch may be issued for the Antelope Valley on Monday night and into Tuesday morning.

There is a chance that Red Flag conditions will persist through Wednesday in the mountains and some valleys, the NWS said.

In Northern California, Pacific Gas and Electric said it was shutting off power to about 87,000 customers Sunday because of fire risks.

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

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 said most customers can expect power to be restored on Monday night.

The Associated Press and Daily News staff writer Eric Licas contributed to this story.