Pacific Gas & Electric says it may cut power to some 1 million people this weekend in central and Northern California, which could see the most unsafe fire weather of the season.
East of San Francisco, the city of Berkeley recommended residents consider leaving the hills before Sunday afternoon, especially if they would have trouble getting out quickly during a fire. He said another round of winds is expected Monday night.
Weather conditions shifted in Northern California on Sunday, with humidity dropping and winds picking up speed, said Scott Strenfel, senior meteorologist for PG&E.
Summit County tweeted that "Field observations and forecasts are indicating that WE WILL NOT meet PSPS [Public Safety Power Shutoff] conditions today." .
On Sunday, the utility shut off power to 225,000 customers in Northern California and later did so for another 136,000 customers in 36 counties. Shutoffs were expected to continue through Monday into the late evening. Southern California Edison said it was considering safety outages for 71,000 customers in six counties starting Monday, with San Bernardino County potentially the most affected.
The company, which pleaded guilty this year to having caused the state's deadliest wildfire, has taken to shutting off its electrical grid to prevent its equipment from sparking new fires.
It said the conditions could equal those during devastating fires in California's wine country in 2017 and last year's Kincade Fire. Fire officials said PG&E transmission lines sparked that Sonoma County fire last October, which destroyed hundreds of homes and caused almost 100,000 people to flee. "So the fire threat remains very high".
Relative humidity levels will plummet, and winds could top 55 miles per hour in valleys, with gusts of 75 miles per hour possible in mountain areas.
"By tomorrow, we'll see relative humidity in the single digits, between 5 and 10%, which is extremely low", he said. Previously, the company announced more expansive blackouts but said it had scaled back in some areas due to shifting weather forecasts.
"It's kind of the typical weather setup that produces these types of events in the autumn months", Dykema said.
Earlier, forecasters with the National Weather Service said the strongest winds of the year were anticipated in some areas of the state through Monday.
"So if any wildfires do break out, there could be a rapid rate of spread and downwind spotting for a significant distance", Sirard said. Thirty-one people have died, and more than 9,000 buildings have been destroyed.
More than 1 million people were expected to be in the dark during what officials have said could be the strongest wind event in California this year.
Lightning in August ignited many of California's biggest blazes, but scientists say climate change has also contributed to the conflagrations. PG&E emerged from Chapter 11 in July after paying US$25.5 billion (S$34.6 billion) to resolve fire claims.
"While this is less than what we saw earlier, these winds are still strong and dry conditions prevail", the agency said on Twitter.
People are cautioned to avoid any activity that could spark a fire, and those in fire-prone areas are advised to assemble emergency supply kits and familiarize themselves with evacuation routes.
It is anticipated to be the highest wind event of the season, he added.
In fact, the cold, dry air mass and clear skies mean that wind-sheltered areas will become chilly at night, with a freeze watch in effect from late Sunday through Monday morning for the Antelope Valley, where temperatures could drop below 26 degrees.