Smoke and ash covering San Francisco: How bad is it and how long will it last? (updated)

Update: Smoke in San Francisco, South Bay, and East Bay is heavier Tuesday than it was Monday. Residents are being advised to stay indoors and, if available, to use breathing masks, per the Bay Area Air Quality Management District.

Because of widespread wildfires in the North Bay that have burned swaths of Santa Rosa and Sonoma since Sunday—“an incredibly fast-moving and dynamic fire,” said Dave Shew, a staff chief with Cal Fire—the weather report in the Bay Area includes smoke and ash.

An estimated 10 to 15 fires in wine country have prompted several evacuations, including cities in Napa, Sonoma, Lake and Mendocino Counties. The Tubbs Fire in Napa County alone has burned 20,000 acres as of Monday and the Atlas Fire in Napa County roughly 5,000 acres.

All of the fires are still ongoing.

Here in the southern portions of the Bay Area, we’re lucky enough to stay put. But what does all of this smoke and ash mean?

How bad is the smoke?

Resident from Sausalito to San Mateo have flooded 911 call centers concerned about smoke in the air. According to the United States Environmental Protection Agency (EPA)’s map, air quality has dropped to “very unhealthy” in all parts of the Bay Area.

Strong winds pushing wind from the northeast to the south fueled the smell of smoke across the region, notes the National Weather Service.

And the U.S. Forest Service’s map shows all weather-monitoring stations in the Bay Area as poor when it comes to air quality.

What does that mean for me?

Today’s air quality means that you shouldn’t try to do much. You should also close your windows and doors to help reduce smoke in your home.

“People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion,” warns Air Quality Index (AQI). “Everyone else should reduce prolonged or heavy exertion.”

Residents as far as the Tenderloin in San Francisco woke up this morning with soot blanketing their homes. And residents as far south as San Jose could smells the stench of smoke.

“I woke up and couldn't figure out why there was dust all over my nightstand and phone,” William Poor, science producer at The Verge and NOPA resident, tells Curbed SF. “I didn't realize it was ash until I left the house and saw all the smoke.”

Major roads and businesses in the area have been closed. People are being advised to stay out of the area for obvious reasons.

Has a Spare the Air Day been called?

No, not yet. But Bay Area Air Quality has issued a smoke advisory.

How long will the smoke last?

Firefighters are still battling the significant blazes., so the smoke will linger in northern parts of the Bay Area. However, according to the National Weather Service, winds have subsided, so the flow of smoke should head west.

“That will help with air quality, for sure,” said Carolina Walbrun, a meteorologist with the National Weather Service. “It will push it out more toward the ocean.”

Has the fire spread to San Francisco?

No, absolutely not.

“If your smelling smoke in SF it is more likely due to the Napa Fire and the Strong winds,” tweets San Francisco Fire Department. “We have NO fires in SF at this moment.”

So, please, do not panic. If you are unsure, call 911 and SFFD will check the area for you. North Bay fire stations,

Update: Gov. Jerry Brown has declared a state of emergency in Napa, Sonoma, and Yuba counties. The order will force thousands of additional evacuations in the area.

We will continue to update this article as the story unfolds.

• Massive fires in Napa and Sonoma burn hundreds of homes and businesses, force evacuations, close hospitals [SF Chronicle]
• Evacuation centers open for North Bay victims [ABC 7]
• Major Wildfires Spread Through Bay Area Wine Country Filling SF Skies With Smoke [SFist]