Southern California Edison has warned roughly 120,000 customers in Los Angeles, Orange, Riverside, San Bernardino and Ventura counties about unprecedented proactive power shutoffs due to Santa Ana winds and wildfire danger.
Most of the deadly California fires over the past several decades, including the fire that destroyed the town of Paradise in Northern California, have been the result of power lines in high-wind situations.
In all, approximately 173,300 customers from nine counties in Southern California are in zones that could face power interruptions, SCE said.
According to SCE:
- Approximately 49,439 customers in LA County including customers in Lancaster, Palmdale, Malibu, La Canada Flintraidge, Pasadena, San Fernando, Santa Clarita, Sun Village, Palmdale and several unincorporated areas may be affected.
- Approximately 40,978 customers in San Bernardino County including customers in Big Bear, Fontana, Hesperia, Rancho Cucamonga, Rialto, San Bernardino, Yucaipa, Yucca Valley and several unincorpoarted areas may be affected.
- Approximately 23,189 customers in Ventura County including customers in Fillmore, Camarillo, Simi Valley, Ventura, and unincorporated areas may be affected.
- Approximately 21,366 customers in Riverside County including customers in Perris, Banning, Beaumont, Calimesa, Hemet, San Jacinto, Menifee, Moreno Valley, Riverside and several unincorporated areas may be affected.
- Approximately 7,250 customers in Orange County including customers in Orange, Rancho Santa Margarita and unincorporated North Tustin may be affected.
- An additional 31,139 customers across Inyo, Kern, Mono and Tulare counties may also face power outages.
For a detailed listing of all areas affected and maps to check if you may face a proactive shutoff, visit SCE's Public Safety Power Shutoff page.
How Proactive Outages Work
Meteorologists and other staff members use high-resolution weather data maps and other tools to monitor extreme fire weather. SoCal Edison also uses weather stations, historical data and fire monitoring cameras to determine fire potential.
If conditions warrant, the utility will shut off power in high-risk areas. Customers can receive notifications about outages in their area through emails, text or phone calls. The utility will alert first responders, local governments and customers of power shutoff.
An initial notification is sent out about two days before a possible shutoff to warn customers. A second notification will be sent a day before, then notifications are sent when power is shut off and when it's restored. Restoration is based on when weather conditions are deemed safe.
Customers can view this map to see whether they're in a high-risk area.
Why Are Outages Being Considered?
Dangerous Santa Ana winds, which can fan flames sparked by downed power lines, are expected to pick up Thursday week as Southern California enters one of the worst times of the year for wildfires.The winds will develop by early Thursday and continue through Saturday, raising the fire risk across Ventura and Los Angeles counties.
"It's strong around 9 a.m. (Thursday), and that's when we could see 50 mph wind gusts, some isolated 60 mph wind in those highest peaks," said NBC4 forecaster Shanna Mendiola. "We still have a red flag warning. We're going to see this Thursday morning through Friday evening. That, in combination with some dry air and dry fuel on the ground, is going to raise that fire threat for us."
Weaker winds are expected in Santa Barbara County. In inland communities, moderate Santa Ana winds are expected Thursday before they decrease Friday.
The fire-whipping winds are produced by surface high pressure over the Great Basin squeezing air down through canyons and passes in Southern California's mountain ranges. They're common in the fall and have a long history of fanning destructive wildfires in the region.
Fall is historically the worst time of the year for damaging wildfires in California. Seven of the state's 10-most destructive wildfires have occurred in October and November.
So far this year, Southern California has not seen the large fires that devastated parts of the state last year, largely due to above-average soil moisture and an active monsoon season that followed a winter of steady rain.
Through September, CALFIRE reported 4,460 wildfires that burned about 40,400 acres. Last year at that time, the agency reported 4,800 fires that burned a staggering 627,600 acres.
California's five-year average for that time period is 324,600 acres.
An onshore flow returns Sunday, bringing cooling to the region.
In Northern California, Pacific Gas and Electric said it would begin cutting off power to around 800,000 customers in 34 counties starting after midnight Wednesday amid forecasts of windy, dry weather.