SANTA ROSA, Calif._Fire officials fear a return to weather conditions similar to those that stoked huge wildfires blazes across Northern California almost a week ago, which could result in fires spreading this weekend, authorities said.
Firefighters throughout the region are facing 10 to 20 mph winds, with gusts up to 40 to 45 mph, said Cal Fire spokeswoman Jaime Williams. The wildfires have charred more than 220,000 acres.
The winds and low humidity "will challenge the firefighting efforts," she said. "When you have these winds, it helps contribute to the spread and the intensity of the fire"
The fires have destroyed an estimated 5,700 structures, resulted in at least 35 deaths and forced upward of 100,000 evacuations. Nineteen people have died due to the Tubbs fire in Sonoma County, eight in Mendocino County, four in Yuba County and four in Napa County.
The Atlas fire had scorched 50,383 acres and was 45 percent contained as of Saturday morning.
Officials battling the Atlas fire expect low humidity and high winds Saturday, with a red flag warning in place throughout the day.
"Firefighters continue to strengthen perimeter control lines, provide structure defense and engage in tactical patrol," a Cal Fire incident report said.
The fire spread slightly along its southern and northwestern edges overnight, officials said Saturday morning.
But the combination of high winds and high temperatures raises the potential for burn areas to expand quickly, they said.
During a night of strong winds, the 46,000-acre Nuns fire in Sonoma County grew by at least 300 acres, threatening the outskirts of the city of Sonoma and the Oakmont neighborhood in Santa Rosa. It was 10 percent contained as of Saturday morning.
A blaze ignited when a downed power line touched a tree branch rapidly grew into a 300-acre blaze on the southwest corner of the Nuns fire, east of Highway 12, Cal Fire officials told firefighters at a morning briefing.
"That's what a little wind can do," Cal Fire spokesman Scott McLean said in an interview. "It's still very volatile."
Officials issued new evacuation orders before 5 a.m. Saturday for a few homes on the northeastern edge of the city of Sonoma.
The Nuns Fire also grew to the north, reaching toward Oakmont and into Annadel State Park. The size of that growth hadn't been determined, McLean said. Evacuation orders were in place for homes north and south of Highway 12 in that area.
Crews continued to gain ground against the 35,270-acre Tubbs fire, which is now 44 percent contained. The nearly 11,000-acre Pocket fire, just east of Geyserville, is 5 percent contained.
A new 100-acre fire erupted in Lake County on Highway 20, about five miles east of Clearlake.
In Mendocino County, the 34,000-acre Redwood fire was 20 percent contained as of Saturday morning.
Officials expect the death toll to rise as search efforts continue in neighborhoods from Santa Rosa to the hills of Napa County.
Officials lifted mandatory evacuation orders for more than 26,000 people in Santa Rosa Friday night.
