Southern California Edison is monitoring weather conditions and has additional crews at the ready to respond to possible power outages and dangerous wildfire conditions due to Santa Ana winds and low humidity predicted through Tuesday night.

Because of the expected conditions, the National Weather Service issued red flag warnings for portions of Los Angeles, Ventura, San Bernardino, Riverside and Orange counties from 10 p.m. on Sunday through 8 p.m. on Tuesday.

In extreme weather conditions, when heat and low humidity combine with high winds, SCE may activate a Public Safety Power Shutoff when power is turned off in a high fire risk area.

Downed power lines are a frequent cause of California wildfires.

SCE continues to explore options for a potential Public Safety Power Shutoff, but no power has been shut off at this time.

SCE is identifying circuits in the following areas, which might be affected by dangerously high winds, and has begun outreach to local officials and customers in advance of a potential decision to shut off power:

Los Angeles County
Parts of: Newhall, Stevenson Ranch, Castaic, Santa Clarita, Valencia, Mount Wilson, Azusa, Covina, Glendora, Mamba Canyon Country, La Canada Flintridge, La Crescenta, Montrose, San Fernando, Sylmar, Monrovia and Pasadena.

Ventura County
Parts of: Camarillo, Fillmore, Moorpark, Simi Valley, Thousand Oaks, Santa Paula, Somis, Santa Rosa Valley and Ojai.

Orange County
Parts of: Orange, Irvine, Silverado, Trabuco Canyon, Rancho Santa Margarita and Trabuco Canyon.

San Bernardino
Parts of: Fontana, Rancho Cucamonga, Alta Loma, San Bernardino, Mt. Baldy, Lytle Creek, Upland, Rialto and Alta Loma.

The power shutoff will not necessarily affect the whole community, only the areas identified as high fire risk.

“We understand the impact turning off power could have on customers,” said Paul Grigaux, SCE’s incident commander.

“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,” he said. “The company’s No. 1 priority is to protect public safety as well as the integrity of the system serving customers.”

How A Public Safety Power Shutoff Works
* Before a power shutoff happens, SCE meteorologists begin running computerized weather simulations of expected weather condition.
* Two days in advance, if the National Weather Service calls a red flag warning, SCE will begin working with local governments and first responders and will notify customers by phone message, text or email that a power shutoff is possible.
* The power will only be shut off after the weather data, confirmed by SCE personnel in the field, show there is an imminent danger of objects such as tree limbs, palm fronds or other vegetation blowing into power lines. The shutoff will be done in consultation with local officials and emergency response personnel such as local fire departments.
* Customers will be notified again when the power is shut off.

If an outage occurs, power will be restored as weather permits and after crews inspect and determine it is safe to re-energize lines.

Customers can report or inquire about outages at 800-611-1911 and get the latest information using the SCE outages app at sce.com/outages. Customers can also get the latest information by visiting sce.com/staysafe or at twitter.com/sce and facebook.com/sce.

Outage Safety Tips
* Remember to check emergency supplies to be sure you have a battery-operated radio, a flashlight and fresh batteries. Do not use candles for lighting as they pose a fire hazard.
* If you’re in a vehicle with a fallen power line on it, stay in the vehicle and remain calm until help arrives. It is OK to use your cellphone to call 911. If you must leave the vehicle, remember to exit away from downed power lines and exit by jumping from the vehicle and landing with both feet together. You must not touch the vehicle and the ground at the same time. Then proceed away from the vehicle by shuffling and not picking up your feet until you are several yards away.
* Power outages in the area may impact traffic signals, and vehicles should treat all intersections as four-way-stops. Use extreme caution.
Use flashlights instead of candles to avoid fire hazards in your homes and businesses.
Water and electricity don’t mix. Water is an excellent conductor of electricity. Do not step in or enter any water that a downed power line may be touching.
* If you use a generator, place it outdoors and plug individual appliances directly into it, using a heavy-duty extension cord. Connecting generators directly to household circuits creates “backfeed,” which is dangerous to repair crews. Please consult the manufacturer’s manual for operating the generator.
* Do not use any equipment inside that is designed for outdoor heating or cooking. Such equipment can emit carbon monoxide and other toxic gases.