Wildfire smoke from Sonoma County hits more Bay Area cities

LATEST July 31, 4 p.m. Smoke from the Woodside Fire is drifting into San Francisco, Oakland and other parts of the Bay Area on Friday afternoon as gusty winds carry it south, officials said. 

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Smoke to the region is being driven by winds from the North Bay over the inner waters and an onshore flow that’s created different pressure gradients, Joe Merchant, a meteorologist with the National Weather Service, told SFGATE. The smoke is expected to stay until the fire is extinguished.

“Our stratus comes in, develops and sort of encompasses the whole Bay Area during the overnight,” Merchant said. 

A Spare the Air alert has been extended to Saturday because of the wildfire smoke, which is the heaviest in the North Bay. The unhealthy air in Sonoma County has prompted several closures and cancellations, including some of the county’s libraries, Rohnert Park’s City Hall building and outdoor programming such as outdoor youth camps and recreational swimming in Santa Rosa and Petaluma, the Press Democrat reported.

According to the Spare the Air website, the air quality in the North Bay as of Friday afternoon is unhealthy for sensitive groups, and it’s moderate in San Francisco, Marin County, the Santa Clara Valley and along most of the Bay Area coast. Parts of the East Bay, from Richmond down to parts of Union City, are also experiencing moderate air quality because of the fire, according to Air Now. 

The air quality remains mostly clear in inland parts of the region, both maps show. 

Wind conditions are expected to peak over the weekend and will continue to draw smoke as long as the fire is active, Merchant said. According to the weather service, gusts of 25 to 30 mph are forecast Friday afternoon through evening, continuing into Saturday. 

The fire is still at 30% containment as of Friday afternoon and has burned 143 acres, according to Cal Fire. In a video update from Cal Fire Incident Commander Marshall Turbeville, he said the rugged terrain has made it difficult for fire crews and that they are letting the fire burn to the Pacific Ocean, noting everything is “looking pretty good.” Cal Fire is working to keep the blaze away from the east side of Highway 1, and officials hope to reopen the road within the next two days, he said. 

July 31, 8:51 a.m. Hot and windy conditions have pushed smoke from the Woodside Fire in Sonoma County farther inland in the North Bay, with residents being warned to take precautions.

Harmful airborne particulates reached hazardous levels in parts of the North Bay, including in Santa Rosa, Healdsburg and Guerneville, due to the Woodside Fire, according to the U.S. EPA Fire and Smoke Map, which warned residents to “stay indoors.”

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Hundreds of firefighting personnel are battling the Woodside Fire, which broke out on Thursday near Highway 1 in Sonoma County and has burned 143 acres and is 30% contained, according to Cal Fire. The cause of the fire is under investigation and no structures have been reported damaged at this point. 

The Bay Area Air District declared a Spare the Air alert through Saturday in response to the wildfire smoke and warned those at risk, including older adults and children, to stay inside if possible with windows and doors closed.

“Smoke can irritate the eyes and airways, causing coughing, a dry scratchy throat and irritated sinuses,” the alert said. “Elevated particulate matter in the air can trigger wheezing in those who suffer from asthma, emphysema or COPD.”

The district said air quality is expected to range from unhealthy for sensitive groups to very unhealthy in Sonoma County and other parts of the North Bay.

Dial Hoang, a meteorologist with the National Weather Service, said weather conditions for the Sonoma Coast on Friday will include sunny and windy weather along the coast with gusts reaching 25 to 30 mph.

“It’s going to get pretty gusty during the day,” he told SFGATE, contributing to “some of the spotting fire that we’ve seen and also pulling the smoke into the North Bay Valley.” 

This weekend, a ridge of high pressure is expected to push temperatures up for much of the Bay Area, with areas of the North and East Bay expected to hit triple digits. Areas along the coast are forecast to remain cooler, reaching highs in the 60s and 70s thanks to the marine layer. 

This breaking news story has been updated.