(Bloomberg) -- Dry, gusting winds will sweep across Northern California early this week, potentially exacerbating a blaze that threatens to torch iconic sequoia trees across the Sierra Nevada and leave thousands of homes without power.

Red flag fire warnings, issued when humidity drops and winds rise, are in place from just south of Lake Shasta through the Sacramento Valley and down the spine of the Sierras until at least Tuesday, the National Weather Service said. Just south of there, more than 800 firefighters and staff are waging a fight against the KNP Complex fire that has caused closures in Sequoia and Kings Canyon National Parks, as well as evacuations through Tulare County.While some parts of the park are still open, visitors are being asked to bring “food, drinks, N95 masks, and a full tank of gas,” according to the park’s Facebook page. “These areas could close with little notice.”

PG&E Corp. said it is planning to cut power to some customers in parts of Northern California as soon as early Monday to prevent its live wires from sparking wildfires during gusty winds. As many as 7,100 homes and businesses in 10 counties, including Napa, could be affected, according to a post Sunday on PG&E’s website.

The wildfire began Sept. 10 after a lightning strike and had consumed 21,773 acres (8,811 hectares) as of Sunday, according to the National Park Service. The fire has produced images of workers wrapping the trees in aluminum foil to protect them from flames. The park is in central California, between San Francisco and Los Angeles.

In addition to the fire threatening the Sequoia, several other large fires are raging across California including the Dixie Fire that has consumed more than 963,000 acres and the Caldor Fire, which has encroached on the area around Lake Tahoe. So far this year, 7,064 fires across California have killed at least 1 person and destroyed nearly 1.97 million acres, according to the California Department of Forestry and Fire Protection, commonly called Cal Fire. 

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