SONOMA, Calif. -- A raging wildfire has forced the evacuation of hundreds of homes after it exploded to thousands of acres in Northern California, authorities said.
The Kincade Fire, ignited Wednesday night, has scorched 16,000 acres and was 5% contained, the California Department of Forestry and Fire Protection, also known as Cal Fire, reported Thursday evening.
More than 550 homes -- with about 1,700 residents -- are under mandatory evacuation orders as the blaze burns uncontrollably, Sonoma County officials said.
Among the communities under mandatory evacuation order was the entirety of Geyserville, about 80 miles north of San Francisco. The Sonoma County Sheriff's Office told residents Thursday morning to leave since the fire crossed Highway 128, heading west.
"If you're in Geyserville," the sheriff's office said, "leave now."
There were 328 personnel from multiple agencies battling the blaze Thursday morning, according to Cal Fire.
Fire comes during intentional power outages
The fire erupted the same day that California's largest utility started another round of intentional power cuts to prevent its equipment from sparking wildfires. It is burning near the outage footprint in Sonoma County, Pacific Gas & Electric officials said early Thursday.
The latest blackouts will continue at least through Thursday in parts of 17 counties, including Sonoma's wine country. Red flag warnings are in place for more than 25 million people in Northern and Southern California, which means soaring temperatures, low humidity and strong winds will increase fire dangers.
Another utility, Southern California Edison (SCE), shut off power to more than 15,000 customers elsewhere in the state, in Kern, Los Angeles, Riverside, San Bernardino and Ventura counties.
Even further south, more than 320 customers in Descanso and Alpine lost power after San Diego Gas & Electric turned it off, citing "high winds and dangerous weather conditions."
Blaze burned 5,000 acres in three hours
The Kincade Fire started at 9 p.m. Wednesday (midnight ET) and torched more than 5,000 acres within three hours, Sonoma County Sheriff's Sgt. Juan Valencia said. At that speed, a football field would be burned every three seconds, according to CNN meteorologist Brandon Miller.
As the fire burned, winds gusted up to 76 mph nearby, the National Weather Service said.
The River Rock Casino has been asked to evacuate, along with additional areas east of Geyserville, the sheriff's office said. The American Red Cross has set up two evacuation centers.
A video of the fast-moving blaze was shared by the Sonoma County Sheriff's Office. It warned residents to be careful. "This is why we issued evacuation orders. Be safe, Sonoma County," it said.
Ash was "falling like snow," early Thursday in the burn zone, fire data scientist Nicholas McCarthy tweeted, referring to the burned residue as "pyrometeors."
In October 2017, the Tubbs Fire ravaged tens of thousands of acres in Sonoma County and killed nearly two dozen people. In Santa Rosa alone, a fire wiped out thousands of homes in the city roughly 50 miles northwest of San Francisco.
Another fire Thursday burned about 75 acres in San Bernardino County, a San Bernardino National Forest Service said. It prompted mandatory evacuation orders.
The Old Water Fire broke out shortly after 2 a.m. and had quickly spread to about 75 acres within a few hours, KTLA reported, citing the forest service. About 80 homes were under mandatory evacuation orders Thursday morning.