Smoke expected to spread across Bay Area today

The smoke plume from the raging Kincade Fire in Sonoma County mostly blew out to the ocean Thursday.

But shifting winds are expected to change that, sending smoke across the Bay Area at the worst levels since last November, when smoke from the Camp Fire in Paradise choked Bay Area residents for two weeks.

“It shouldn’t be as bad as the Camp Fire, but it will be like a winter day where everybody is burning in their chimneys and we have stagnant cold air,” said Charley Knoderer, a meteorologist with the Bay Area Air Quality Management District in San Francisco.

The district issued a Spare the Air alert for today across all Bay Area counties.

“If you smell smoke, definitely stay inside, and try to stay in a place that is air conditioned,” said Knoderer. “If you are in your car, put the air on recirculate. And don’t go jogging.”

Forecasters are predicting the smoke will impact San Francisco International Airport beginning as early as 11 a.m. today and will continue spreading across the Bay Area.

The district’s forecast for today shows that the air quality index, a measurement used by the U.S. Environmental Protection Agency, is expected in all nine Bay Area counties to reach a level considered “unhealthy for sensitive groups” like the elderly or people with respiratory problems. In other words, the levels of particulate matter, or soot, in the air are expected to be roughly the same across the Bay Area today as they were Thursday in the North Bay, closer to the where the fire is burning.

Specifically, the forecast calls for an air quality index reading of 110 today in the North Bay, 105 on the Peninsula and in the East Bay, and 102 in the Santa Clara Valley.

Winds are more difficult to forecast than some other weather features, so some uncertainty remains.

“There is a massive plume of smoke now that extends into the North Pacific,” Knoderer said. “The change in the winds could push that back over the Bay Area.”

When air quality worsens, experts recommend limiting exposure. If you must be outside, minimize strenuous activity. To the extent possible, stay indoors where air is filtered and keep windows and doors closed, they said.

So far, 2019 has been a mild fire year across California. But the smoky air coming from the Kincade Fire rekindled memories of last November, when huge plumes of choking smoke from the Camp Fire, which devastated the town of Paradise, blew south from Butte County and made air pollution levels in the Bay Area among the worst in the world for roughly a week.

During the week of Nov. 12, the AQI hit 228 in San Francisco, 220 in Oakland and 247 in Vallejo — levels considered “very unhealthy” for all groups. In San Jose, the levels that week reached 194 or “unhealthy.” Those levels were among the worst recorded in the Bay Area since 1999, when modern particulate readings began.

During last year’s very smoky November, Bay Area residents began flocking to hardware stores to buy N95 masks, the white face protectors often used by people during home improvement projects.

But last month, the Association of Bay Area Health Officials announced that they might not be all that people are expecting.

“There is no clear evidence that N95 respirator use is beneficial during a wildfire smoke event,” the organization said in a statement.

Health officials have noted that the masks don’t fit small children, and for people with facial hair, the masks often still leave openings.

“There isn’t a great deal of science behind the benefit of these for smoke, and I think the recommendation our health officers are making is important,” Marin County Fire Chief Jeff Weber said in an interview with KCBS last month to discuss the group’s recommendation.

Instead, experts say, stay indoors if the smoke is bothering you. If you are hot and don’t have air conditioning, go to a shopping mall, movie theater or library.

The weekend forecast has good and bad news. Winds are expected to pick up across the Bay Area, blowing out to sea. That will be good to remove smoke. But given the dry, humid conditions, it also increases the risk that a wildfire will spread out of control if it starts.

“We have to be very cautious,” said Knoderer. “It’s touch and go.”