Rain clouds that blew in from the Pacific Ocean on Thursday helped firefighters make substantial progress on the King fire, with the huge blaze in El Dorado and Placer counties more than half contained for the first time since it started nearly two weeks ago.
The cool air and high humidity that accompanied the first fall showers alleviated the drought conditions that allowed the fire to race through the rugged river canyons of the Sierra Nevada.
By Thursday evening, authorities said the 95,347-acre fire was 55 percent contained, up from 43 percent on Thursday morning. With damp weather expected to continue through Saturday, officials talked about sending home some of the more than 8,000 personnel battling the blaze – the largest wildland firefighting force ever assembled in California.
“We had so much rain that we pulled nearly all the operational crews off the fire lines midday,” said Mike McMillan, a spokesman for the fire’s northern command center. “For a good part of the day, we let Mother Nature handle it.”
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Dana Walsh, a United States Forest Service spokeswoman for the fire’s southern region, said the rain and efforts of firefighters had combined to slow the fire’s march through the Rubicon River drainage area about halfway between Highway 50 and Interstate 80.
“We had several hours of downpours on portions of the fire,” Walsh said. “This rainfall was not enough to the put the fire out, (but) we’re talking about demobilizing crews. As things are winding down, the resources at risk are being reduced.”
The rain also resulted in officials issuing a flash-flood warning Thursday, with the danger of mudslides and debris flows from the fire-ravaged hillsides. That warning was called off later in the day without any reports of flooding.
“Overall, we welcome the rain, and if we can get more we’d love it,” said Dennis Mathisen, a spokesman for the California Department of Forestry and Fire Protection. “It helps lay down the flames and gives firefighters more ample opportunity to fortify the containment lines. But the flip side to it is there’s the potential for mudslides and debris flows in the fire area itself.”
Changing conditions also allowed some evacuated residents to return to their homes, at least for now.
The El Dorado County Sheriff’s Office, which has overseen the evacuation of rural residents, said the mandatory evacuations of two tiny communities had been changed to voluntary evacuations.
“With today’s weather and the decreased fire activity within the Rubicon River drainage area, the threat to the communities of Volcanoville and Quintette has been reduced,” the office said on its website. Residents will have to leave if the weather changes and the fire flares up, authorities said.
After the current low-pressure system blows through, the days will turn dry and warmer starting Sunday, according to the National Weather Service. But for at least the next couple of days relief will come in the form of cool and potentially wet weather.
The forecast for the foothills of central El Dorado County calls for a 20 percent chance of light showers Friday and Saturday with high temperatures in the low-60s.
Relative humidity will remain high in the fire area, said Craig Shoemaker, a Weather Service meteorologist in Sacramento. Low humidity helped the fire spread after it started Sept. 13, but relative humidity will be in the 80 percent to 100 percent range overnight Thursday and will stay high for the next couple of days, he said.
“You’d think that would put a damper on the fire,” Shoemaker said. “We’ve had nights where we were only getting up to 40 percent, so that’s a big improvement.”
On Thursday, the area of the fire received up to an inch of rain, while downtown Sacramento saw only about a third of an inch. Clouds tend to dump more rain as they rise up the western slope of the Sierra, the meteorologist said.
“When (a wet weather system) flows out of the west, the moisture is lifted and released. They typically get more precipitation up there,” Shoemaker said.
For firefighters, that meant a reprieve from the hot, parched battle they had been fighting for 12 days. It also meant camps were sodden and covered in muck, McMillan said. Trenches had to be dug to divert water away from tents.
The weather also made for slippery, twisting roads and a few minor accidents, he said.
“All the heavy equipment has a difficult time in muddy conditions,” McMillan said. “The roads are narrow and even though they’re paved ... it’s very treacherous.”