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 10,000 acres, the California Department of Forestry and Fire Protection, also known as Cal Fire, reported Thursday morning.

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.

Winds are expected to die down in Northern California by the afternoon, CNN meteorologist Chad Myers said, but could pick back up on Sunday.

Another big wind event is forecast later Thursday for Southern California, Myers said, where gusts could reach up to 65 mph.

"One spark will take a fire a long way," Myers warned.

Southern California Edison (SCE), another utility in that part of the state, 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 rate, 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.

Old Water Fire threatens Southern California

Another fire in San Bernardino County in Southern California prompted mandatory evacuation orders for at least 80 homes, according to the San Bernardino National Forest Service.

The Old Water Fire broke out around 2 a.m. Thursday and spread to about 75 acres within a few hours, the forest service said. An evacuation center has opened at San Gorgonio High School.

Firefighters were making progress Thursday morning, the forest service said, but containment was still at zero percent.

Approximately 400 personnel were fighting the Old Water Fire, aided by 50 fire engines and a helicopter.

https://ktla.com/2019/10/24/kincade-fire-forces-evacuations-north-of-san-francisco-in-sonoma-county/