(Bloomberg) -- Californians are facing the largest mass blackout so far this year as the state’s biggest utility, PG&E Corp., prepares power shutoffs to prevent live wires from falling into dry brush and igniting wildfires with ferocious winds expected to sweep across the region.PG&E is planning to cut power to 386,000 homes and businesses -- an estimated 1.2 million people -- across Northern California starting at 10 a.m. Sunday, company officials said at a press briefing late Saturday. That’s down from an initial projection of about 466,000 customers given on Friday. The outages are poised to hit 38 counties that include the San Francisco Bay area, the Sierra Nevada foothills, the Central Valley and the Central Coast. A final decision on the blackout will be made Sunday morning.“This event looks particularly dangerous due to a combination of factors that we continue to track,” said Scott Strenfel, PG&E’s head of meteorology and fire science. Bone dry air will accompany the strong winds that are expected to pick up throughout the day on Sunday, he said. Edison International’s Southern California Edison said 56,500 customers could lose power -- affecting about 170,000 people. The power cuts could begin Monday morning for residents who live in mountainous areas around Los Angeles where dry Santa Ana winds will blow, a spokesperson said by phone. The potential blackouts would be the latest blow for a state that’s been battered by extreme weather and has already seen a record 4.1 million acres (1.66 million hectares) scorched this year. PG&E has preemptively cut power four times in 2020 to prevent falling wires from igniting blazes in a region that’s tinder dry from heat and drought. The new round of outages would be the biggest by far, stretching across much of PG&E’s service territory.Winds starting this weekend are forecast to reach 70 miles (113 kilometers) per hour in the northern part of the state, with gusts expected to last through Tuesday morning. By Monday, humidity will be as low as 6% in Redding and just 5% in Grass Valley, according to the National Weather Service. It comes as the state is already riddled with dry brush and grasses due to the hottest average temperatures over the last six months, according to records that go back 126 years, said Strenfel of PG&E. The blackouts may hit densely populated parts of the San Francisco metropolitan area, including portions of Oakland, Berkeley and Marin County -- cutting power to many residents as they are working from home due to the coronavirus pandemic. The city of Berkeley advised residents living in the hills to evacuate due to the fire risk, according to a statement. San Francisco, at relatively low risk of fires, is the only county in the Bay Area region not expected to be affected.PG&E and Southern California Edison aren’t the only utilities warning of outages. Pacific Power, owned by Warren Buffett’s Berkshire Hathaway Inc., said Friday that it could switch off power for about 5,800 customers in Northern California and Southern Oregon on Sunday due to the gusts, according to a statement.Much of the U.S. West is at risk from wildfires as dry weather and stiff winds turn hillsides, forests and scrub land into tinderboxes. In Colorado, two of the largest fires in state history have forced the closure of Rocky Mountain National Park and triggered the evacuation of nearby towns. More than 8 million people across California will be in high-risk zones, including the cities of Sacramento, Stockton, and San Bernardino, the U.S. Storm Prediction Center said in its long-range forecast.The looming outages come on the heels of a blistering heat wave that gripped California earlier this month, driving temperatures to record daily highs. In August, a freak lightning storm sparked more than 150 wildfires in 24 hours. Days before that, the state’s grid operator ordered the first rotating outages since the Enron-era energy crisis of 2001 as scorching weather sent electricity demand surging.PG&E began resorting to preventative shutoffs after its equipment caused some of California’s worst blazes, forcing the company into bankruptcy last year. PG&E emerged from Chapter 11 in July after having paid $25.5 billion to resolve fire claims.“They have a lot of work to do not just to restore their power but to restore the trust that they have failed to earn over the course of decades,” Governor Gavin Newsom said during a briefing Friday. “That is self-evident to anyone living in the Bay Area.”(Adds comment from PG&E official starting in fourth paragraph)For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2020 Bloomberg L.P.