Sonoma County mustering more fire resources before heat and winds return
Firefighters battling the 4-day-old Glass fire were in a race against time Wednesday, striving to tamp down flames and strengthen containment lines ahead of renewed winds and triple-digit heat.
With the the risk of increased fire activity and shifting flames looming, clearer air Wednesday afternoon opened a window for aircraft to aid ground troops attacking hot spots in already burned areas of the 51,266-acre blaze, an effort to prevent winds from the northwest expected Thursday from stirring up fresh flames and producing embers that could blow beyond fire lines and spread the blaze already torching large areas of Sonoma and Napa counties.
The fire has burned most aggressively the past two days in rugged country along its northern front, primarily around the city of Calistoga and the southern flanks of Mount St. Helena near Robert Louis Stevenson State Park, as well as in the wooded area between Petrified Forest and Saint Helena roads in Sonoma County.
Additional evacuations and warnings were announced Wednesday evening along Highway 29 near the Napa-Lake county line and what Cal Fire Division Chief Ben Nicholls said had been the “most active portion of the fire and, for the entire complex … the priority piece for today.”
But a shift in winds forecast for Thursday afternoon is expected to put pressure on the southeastern edges of the fire. A red-flag warning for increased fire danger is set to last until 6 p.m. Friday, with upper elevation gusts of 25 to 35 mph.
Fire officials say they’re concerned about the potential need to defend Kenwood and other Sonoma Valley communities, as well as Yountville and southern Napa Valley.
The proximity of the fire front in Sonoma County to the Mark West Creek drainage has sparked additional alarm about the unthinkable: that flames could break through the lines and run some of the same route toward Santa Rosa as the devastating Tubbs fire in 2017.
That whole area east of Calistoga Road past St. Helena Road toward Porter Creek has been troubling, with “pretty good land burning off every day,” Santa Rosa Fire Chief Tony Gossner said Wednesday.
When the wind comes up each afternoon, it raises columns of smoke that hold the potential for ember fallout to start new fires, so crews have been pushing into the burn zone 200, 300 feet trying to cool everything down as much as possible, he said.
It’s hard to see where the hot spots are until there’s wind on the area, making them smoke, but if the if the gusts stay at 1,000 feet and above, as predicted, that area may come through the next two days OK.
If gusts mix lower, toward the ground, as happened last weekend — contrary to predictions — the winds could get into the drainage, pushing flames into the drainage against the wind, he said.
“We won’t know until it actually happens,” said Gossner.
In preparation, Cal Fire crews ran bulldozers on rural roads east of Calistoga Road on Wednesday, trying to cut off any advance the fire could make westward.
The mix of fuels that now mark the footprint of where the Tubbs fire wrought so much devastation is likely to present both advantages and disadvantages to crews tackling another round of flames should they reach that far west, Cal Fire Operations Chief Mark Brunton said during a news briefing Wednesday.
While the heat and energy of the Tubbs fire was aided by decades of both dead and living fuel that were mostly burned away that October night in 2017, its footprint today would present a different kind of firefight, Brunton said.
“It cleaned out all those heavier down and dead fuels so you don’t have that fuel load that you used to, but it changed to a lighter fuel so the fire brands will get into that lighter fuel, the grass, the light brush that has grown back, some of the immature trees, so it’s more receptive and easier to catch fire,” he said.
And if it does, it will burn with less intensity but more speed.
“It’s kind of a double-edged sword,” he said. “Yeah, it’s more receptive, but the intensity of the fire will be lessened because it’s gone through that change.”
To that end, crews worked Wednesday to cut lines around Gates, Sharp and Diamond Mountain roads in the hills east of Calistoga Road and north of the devastated St. Helena Road area.
“Bulldozers are looking to meet in the middle,” Nicholls said during a Wednesday afternoon briefing. “Bulldozers are the tool of choice at this point due to lack of hand crews.”
But the topography of the land and the narrow, rural roads made access difficult. Midday Wednesday, crews scouted potential routes to take deep on heavily wooded Sharp Road.