SAN FRANCISCO (CBS SF) — With red flag warning conditions packing howling winds predicted for late Saturday, Pacific Gas & Electric officials went forward with the second planned power shutoff this week because of mounting fire danger conditions from the Bay Area to the Sierra.

Pacific Gas & Electric said the blackouts began around 2 p.m. Saturday in parts of 36 counties. About 940,000 customers — more than 2 million people — will be affected.

It’s the third preventative shutoff in as many weeks amid concern that gusty winds could knock down power lines and spark fires.

According to PG&E, the outage timeline is:

  • 5 P.M. Saturday, Oct. 26 — Amador, Butte, El Dorado, Glenn, Nevada, Placer, Plumas, San Joaquin, Sierra, Shasta, Tehama, Yuba
  • 6 P.M. Saturday, Oct. 26 — Colusa, Marin, Mendocino (south), Napa, Solano, Sonoma, Yolo
  • 8 P.M. Saturday, Oct. 26 — Alameda, Contra Costa, Monterey, San Benito, San Mateo, Santa Clara, Santa Cruz, Stanislaus
  • 9 P.M. Saturday, Oct. 26 — Humboldt, Lake, Mendocino (north), Siskiyou, Trinity
  • 12:01 A.M. Sunday, Oct. 27 — Alpine, Calaveras, Mariposa, Tuolumne

Winds picking up Saturday night could gust to more than 85 mph (137 kph) and make conditions extremely difficult for firefighters trying to tame a huge blaze in wine country.

The utility referred to a “historic wind event” in a Friday news release, stating that models “indicate the weather event could be the most powerful in California in decades, with widespread dry Northeast winds between 45-60 miles per hour and peak gusts of 60-70 mph in the higher elevations.”

The number of planned outages in Marin County was bumped up to 118,535.

Here is a breakdown of the anticipated number of customers affected this weekend in each Bay Area county:

  • Alameda County: 57,002 (outage will impact cities of Albany, Berkeley, Canyon, Castro Valley Dublin, Fremont, Hayward, Livermore Oakland, Piedmont, Pleasanton, San Leandro and Sunol)
  • Contra Costa County: 48,058 (outage will impact cities of Alamo, Antioch, Brentwood, Byron, Canyon, Clayton, Concord, Crockett, Danville, Diablo, El Cerrito, El Sobrante, Hercules, Kensington, Knightsen, Lafayette, Martinez, Moraga, Orinda, Pinole, Pittsburg, Pleasant Hill, Port Costa, Richmond, Rodeo, San Pablo, San Ramon and Walnut Creek)
  • Marin County: 118,535 (outage will impact cities of Belvedere, Bolinas, Corte Madera, Dillon Beach, Fairfax, Fallon, Forest Knolls, Greenbrae, Inverness, Kentfield, Lagunitas, Larkspur, Marshall, Mill Valley, Muir Beach, Nicasio, Novato, Olema, Point Reyes Station, Ross, San Anselmo, San Geronimo, San Rafael, Sausalito, Stinson Beach, Tiburon, Tomales and Woodacre)
  • Napa County: 17,878 (outage will impact cities of Angwin, Calistoga, Deer Park, Lake Berryessa, Oakville, Pope Valley, Rutherford, St Helena and Yountville)
  • San Mateo County: 57,218 (outage will impact cities of Belmont, Burlingame, Daly City, El Granada, Emerald Hills, Half Moon Bay, Hillsborough, La Honda, Loma Mar, Montara, Moss Beach, Pacifica, Pescadero, Portola Valley, Redwood City, San Bruno, San Carlos, San Gregorio, San Mateo, South San Francisco, Woodside and unincorporated communities in Southwest San Mateo County)
  • Santa Clara County: 27,094 (outage will impact cities of Coyote, Cupertino, Gilroy, Los Altos, Los Altos Hills, Los Gatos, Monte Sereno, Morgan Hill, Redwood Estates, San Jose and San Martin)
  • Solano County: 25,524 (outage will impact cities of Fairfield, Suisun City, Vacaville and Vallejo)
  • Sonoma County: 95,647 (outage will impact cities of Medical Baseline: 2,695
    Annapolis, Bodega, Bodega Bay, Camp Meeker, Cazadero, Cloverdale, Cotati, Duncans Mills, Forestville, Freestone, Geyserville, Glen Ellen, Graton, Guerneville, Healdsburg, Jenner, Kenwood, Larkfield, Monte Rio, Occidental, Penngrove, Petaluma, Rio Nido, Rohnert Park, Sebastopol, Stewarts Point, Valley Ford, Villa Grande and Windsor)

Although San Francisco wasn’t listed as part of the potential shutoff area, the National Weather Service wind advisory was updated to include the San Francisco Peninsula, including the city of San Francisco and the San Francisco Bay shoreline, NWS said Friday evening.

The utility said the outages were needed because of the threat of destructive and deadly wildfires. Currently, firefighters were battling a 25,000-acre plus wildfire near Geyserville that has destroyed 77 structures, forced thousands to evacuate and may have been sparked by PG&E transmission lines during a red flag warning event Wednesday night.

“We are preparing for what is likely going to be a widespread safety shutoff across our service territory to combat the risk of a catastrophic wildfire,” said PG&E executive Sumeet Singh.

PG&E officials said they’ve learned from this week’s outage after admitting they only shut off low-voltage lines and not high-voltage transmission lines prior to the Kincade Fire because winds weren’t strong enough.

“We have revisted and adjusted some of our standards and protocols to determining when we will deenergize a high voltage transmission line,” said PG&E president Andy Vesey.

He said if power lines are in areas with higher winds than forecast because of topography — for example, ridges that act as wind tunnels — those lines will likely now be shut off.

The outages may be widespread and so is anger and frustration among customers.

PG&E officials confirmed some are having their power shut off when they don’t necessarily live in an area impacted by high fire danger or winds.

“One of the things that we’re committed to do as soon as we get through fire season and we can sit back is to really think about what additional sectionalizes we need to put in, how we might be able to reconfigure the system, so that areas that don’t typically see bad weather but are somehow connected through the system will not be impacted,” Vesey said.

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