Hot weather, low humidity and bone dry vegetation caused by the worst drought in decades was fueling the blaze and challenging fire crews, Patterson said.
"The fire is moving quickly. This fire was throwing embers out in front of itself for up to 2 miles yesterday," Patterson said. "These are exceptional fire conditions."
About 1,700 residents in the area were put under mandatory evacuation orders Friday night.
Pacific Gas & Electric said on its website that more than 2,600 homes and businesses in the area had lost power as of Friday afternoon and there was no indication when it would be restored. "PG&E is unable to access the affected equipment," the utility said.
A shoeless older man attempting to flee the blaze on Friday crashed his sedan into a ditch in a closed area and was helped by firefighters. He was safely driven from the area and did not appear to suffer any injuries. Several other residents stayed in their homes Friday night as the fire continued to burn nearby.
The cause of the fire was under investigation, Cal Fire said.
Meanwhile, firefighters have made significant progress against a wildfire that began in Yosemite National Park and burned into the Sierra National Forest.
The Washburn Fire was 79% contained Friday after burning about 7.5 square miles (19.4 square kilometers) of forest.
The fire broke out July 7 and forced the closure of the southern entrance to Yosemite and evacuation of the community of Wawona as it burned on the edge of Mariposa Grove, home to hundreds of giant sequoias, the world's largest trees by volume.
Wawona Road is tentatively set to reopen on Saturday, according to the park website.
