Ash from a growing wildland fire in Yolo County is blowing into the Bay Area, leaving a dusting of visible particles in the East Bay and contributing to hazy skies, bad air and a dramatic sunset Saturday night.
The County Fire, as it’s being called, is located along Highway 16 near the town of Guinda. It started Saturday afternoon and had burned more than 22,000 acres and has crossed into Napa, as of late Sunday morning, according to Cal Fire, the state’s firefighting agency.
Northerly winds are carrying smoke from the County Fire into the Bay Area, and a weather phenomenon called “vertical mixing” is forcing the smoky air down, close to the surface, said Lisa Fasano,a spokeswoman from the Bay Area Air Quality Management District.
The smoky air — from burned grasses, brush and trees — can pose health risks, especially for people with respiratory conditions such as asthma or bronchitis.
People should avoid directly breathing the smoke and ash as much as possible, Fasano said, by closing their windows and staying indoors. The body’s natural defense mechanisms can help eliminate larger particles through coughing or by producing mucus that’s coughed or swallowed, she said.
People with preexisting heart and lung conditions are particularly vulnerable to the effects of fire smoke, and should consider going to a place with filtered air, such as a shopping mall or library, she said.
“The winds are probably going to keep blowing the smoke in this direction and mixing it down today,” Fasano said.
“People who are in the smoke pattern should keep their windows and doors closed and put their air conditioner units on recirculate do it doesn’t draw in ash.”
Fruits and vegetables from smoky areas should be thoroughly washed before eating. Accumulated ash on cars or outdoor surfaces such as patios can be hosed down with water.
It’s unclear which areas of the Bay Area are most impacted by the Yolo County smoke. The air district will try to have air circulation weather maps on its website soon, Fasano said.
While people are seeing ash and yellowed air, the overall air quality of the Bay Area was still good Sunday according to measurements used by the air district. This may be because the smoky air is passing in ripples the district’s monitors don’t detect, Fasano said.
“What often happens with smoke that’s blowing in, is it can blow in very narrow bands that can bypass the monitors. I suspect that’s what’s happening,” Fasano said.
“That’s not to say there’s not smoke in the air and it’s not impacting people,” she added.
Healthy air was also showing on the real-time nonprofit World Air Quality Index, which uses data from many sources. Check the data here.
The air quality can change with weather pattern changes.
Many East Bay residents, including in Berkeley, reported on social media Sunday that small particles of gray dust or soot had settled on their cars, plants, decks and patios. People also said they saw particles in the air.
A woman in El Cerrito wrote on the social media site NextDoor:
“I came outside this morning to discover my car covered in white soot. I assume that it’s coming from the fires to the North….. I took my car to get it washed, then returned, and realized that the soot is still falling. Just a heads up.”
Someone from Poet’s Corner in Berkeley wrote:
“Yes, there is a strange amber quality to the light this morning, and ash continues to settle all over our deck and car.”
The smoke made Saturday’s sunset dramatic.
Look up! Crazy sun through smoky skies right now in the SF Bay Area. pic.twitter.com/abLMAFfFk7
— SchofieldImages (@SchofieldImages) July 1, 2018
A second fire is also still burning in the North Bay.
Evacuations were ordered for both fires.