Sonoma Valley stuck between regional disasters

Don’t breathe the air. That impossible warning was raised on Thursday when the Sonoma Valley came under a Purple Air Health Alert – according to the popular air quality monitoring technology, built on a monitoring crowd-sourced network of sensors that measures the air quality index (AQI).

The Valley sits between two mid-summer large wildfire events, the LNU Lightning comples of Lake, Napa and Solano counties, and the Walbridge fire of west Sonoma County. But while there was little damage to property or acreage in the Sonoma area to this point, the biggest impact was everywhere, in the air.

The AQI measures ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide and nitrogen dioxide on a 1-500 scale.

Any reading from 201-300 puts people who breathe it at risk for damage to sinus and lungs, even permanent damage, and is considered worthy of a Health Alert: “Everyone may experience more serious health effects if they are exposed [to the level] for more than 24 hours.”

Purple Air has become a popular way to check the AQI in any given area. At 1:30 p.m. on Thursday, Aug. 20 – the air in downtown Sonoma visibly heavy with smoke – the Purple Air reading near the Plaza was 205. Other readings around the Valley ranged from 169 to 205 although Petaluma’s readings at the same time were between 9 to 84, and downtown Napa’s ranged from 125 to 144.

Fortunately, sheltering in place has become second nature to everyone by now - doors and windows closed if possible - but many Sonoma County residents have had to evacuate their homes and many more are under evacuation warnings.

Fires to the west, smoke to the east

Cal Fire Operations Chief Charlie Blankenheim confirmed at a Thursday morning press briefing that the Walbridge fire burning north of Guerneville and west of Healdsburg has become the department’s top priority among the cluster of fires within the LNU Lightning Complex.

The Walbridge fire has burned across 14,500 acres. Though earlier the fire remained about halfway up the narrow, winding Mill Creek Road, rising winds turned it eastward Wednesday afternoon and pushed it in the direction of the Highway 101 corridor, said Chris Godley, the county’s Director of Emergency Management.

“The fire remains a significant threat to communities all along its border,” Blankenheim said. “The fire behavior is erratic. It can move in any direction. And at this time, we are looking also for potential slight shift in the weather today, which could also pose challenges in understanding and anticipating the fire behavior.”

Meanwhile the LNU fires in Sonoma, Napa and Lake counties grew to 131,000 acres and had destroyed 105 structures. It remains uncontrolled as of 8:15 Thursday morning, Cal Fire announced.

The Hennessey fire, which includes the merged Gamble, Green, Markley, Spanish and Morgan fires, has burned 105,000 acres in Napa County and destroyed one house and two outbuildings. That is an increase of about 5,000 from overnight.

Response staff depleted

Local Sonoma County firefighters had already been deployed to help elsewhere in the state when the Walbridge fire, initially called the 13-4 fire, broke out Monday. One strike team — comprised of five engines and a battalion chief — returned to the county and two strike teams remain deployed on the River fire in San Benito County and the Hennessey fire in Napa County, according to Sonoma County Fire District Chief Mark Heine.

“The mutual aid system in the state of California is stretched like never before,” said state Sen. Mike McGuire, D-Healdsburg. “We have every available firefighter either on a fire line or providing station coverage in their community.”

Though still substantially understaffed in terms of ground crews and air resources, according to Cal Fire Division Chief Ben Nicholls, firefighters confront the growing threat with the resources they can gather. The immediate threat to densely populated communities has earned the county greater air support as the firefight continued, including an air attack plane that will be dedicated to Sonoma County to help coordinate the firefight, and additional air tanker flights in the afternoon, said Nicholls, who is supervising the Sonoma County’s efforts.

Bags packed and ready to roll

Though officials have described intense heat and towering flames over 100 feet on this week’s wildfires, cooler, moister and calmer weather overnight and Thursday morning has made for less explosive wildfire growth than Sonoma County residents have experienced in the past few years.

But officials urged residents to heed evacuation orders and to prepare to leave home if they are under warnings.

“I know that some people are, you know, relieved that homes are not on fire right now on the valley floor in, you know, Guerneville and the lower Russian River. And yet, just as a reminder, this fire is zero percent contained,” said Sonoma County Supervisor Lynda Hopkins, whose district encompasses the fire zone.

“So it's still really critical that this is taken extremely seriously. And if you are in a mandatory evacuation zone, we just remind you to please get out, because that's the most important thing. In order for our firefighters to fight the fire, folks need to be out of their homes and safely relocated.”

Supervisor James Gore, who lives at the edge of Healdsburg, where all 12,000 residents were placed under evacuation warning on Wednesday night, reiterated her words, noting that he and his family packed their important documents and belongings and staged them at a friend’s home.

“While you and we and even the firefighters cannot control this fire, and zero percent (is) contained, you can control your actions,” he said.

The Walbridge fire prompted an evacuation warning for the city of Healdsburg on Wednesday, and was threatening the Russian River communities of Guerneville and Rio Nido.

Mary Callahan, Phil Barber, Lori Carter, Julie Johnson, Lorna Sheridan and Christian Kallen from the Santa Rosa Press Democrat and Sonoma Index-Tribune contributed to this story.