HEALDSBURG, Calif. — Popular downtown boutiques and farm-to-table restaurants were deserted in Healdsburg, Calif., by Saturday afternoon. Traffic ground to a halt in downtown Windsor, where lines for gas stations spilled into gridlocked roadways. The county fairgrounds in Santa Rosa once again morphed into a disaster base camp.

Even an evacuation center in Sonoma County had to be evacuated.

Two years after the devastating Tubbs fire killed 22 people in the region, officials were taking no chances with the menacing Kincade fire and the threat of high winds that could spread the flames overnight. County officials ordered the mandatory evacuations of nearly 90,000 people on Saturday, and Pacific Gas and Electric started shutting off power for almost a million customers in Northern California.

“The next 72 hours are going to be challenging,” Gov. Gavin Newsom said at a news conference on Saturday afternoon. “I could sugarcoat it but I’m not. We’re in an anticipatory stage that is rather anxiety inducing.”

State fire officials hoped that by preparing for the worst-case scenario, they could avoid major destruction from the Kincade fire, which has already consumed nearly 26,000 acres and was 10 percent contained as of 6:30 p.m. local time, according to Cal Fire, the state’s fire agency. The fire has so far destroyed 77 structures, including 31 homes, and damaged another 14 structures, the authorities said.