Cooler temperatures, lighter winds and higher humidity levels on Tuesday helped efforts to contain the wildland blaze burning across parts of Yolo and Napa counties, though hundreds of residents on the fire’s southern edge were put on notice that they may have to evacuate should flames continue their southward march.
A smaller number of rural residents on the north end of the fire were ordered to evacuate late Tuesday due to the blaze’s potential spread.
The County fire, burning mostly in the rugged hills east of Lake Berryessa, had grown Tuesday night by more than 12,000 acres — a small fraction of the gains it made after erupting Saturday and quadrupling in size to 60,000 acres by Monday evening.
The 72,500-acre blaze, the largest wildland fire in California this year, was threatening nearly 1,000 structures Tuesday, about 10 times the number of buildings considered at risk on Monday. Most were seasonal and year-round homes along the Highway 128 corridor, which runs along the southern end of Lake Berryessa.
“It burned very actively overnight (Monday), was still burning in the morning and is still burning now,” said Cal Fire Capt. Jordan Motta. “But today’s looked more favorable weather-wise as opposed to the first few days. Lower temperatures, winds were a lot lighter and the humidity was really up and helping us with our firefight.”
Containment was reported at 15 percent on Tuesday evening and Cal Fire officials said they hoped that full control of the blaze could be achieved by July 10.
Shifting winds each day have pushed the fire south in the mornings and back north in the late afternoons, leading authorities to advise residents along Highway 128 of their need to potential need to evacuate should the flames race south.
Along the northern front, the area placed under mandatory evacuation late Tuesday was bounded by Highway 16 on the east, Berryesssa-Knoxville Road on the west, Old County Road on the north and County Road 53 on the south end. The Napa County section had no permanent residences, authorities said.
So far no structures have been lost to the fire, which on its eastern and northern flanks has brushed up against the boundaries of the Berryessa Snow Mountain National Monument. On Tuesday, due to fire danger, the Bureau of Land Management, which helps manage the monument, closed the Knoxville Recreational Area, a public OHV park that includes the Hunting Creek Campground.
Further north, the Mendocino National Forest implemented seasonal campfire restrictions across a vast swath of the mountains separating the Highway 101 corridor and the Sacramento Valley.
At its greatest extent, the County fire measures nearly 18 miles long, a span that Motta, the Cal Fire captain, compared to the shape of a feather or fern leaf. He said that pattern is indicative of a wind-driven wildfire.
With reinforcements arriving en masse, the firefighting force on the blaze nearly doubled Tuesday, up to 2,162 personnel — almost 1,000 more than the night before .
Petaluma Fire Department Capt. Chad Costa got the call Sunday night to report Monday morning for an assignment of up to 14 days.
During a 24-hour shift Tuesday, he worked as a safety officer, acting as another set of eyes looking out for hisfellow firefighters on the southern end of Lake Berryessa who were building protection lines at the Monticello Dam in Napa County.