CZU Lightning Complex: Thick Layer Of Smoke Drifts Over Bay Area; Air Quality At Hazardous Levels

SAN FRANCISCO (CBS SF) -- A layer of unhealthy, smoky air from the CZU Lightning Complex wildfire stalled over the San Francisco Bay Area Friday, triggering an air quality warning and forcing local residents to remain indoors with their windows closed.

UPDATE: Some Evacuation Orders Lifted In Santa Cruz County

The offshore winds that had helped clear out the Bay Area skies on Thursday had all but disappeared. Combined with a marine layer of low fog, the overcast skies turned cloud-covered and gray.

"The stable air mass may also play a role in decreased air quality over places like the SF Peninsula as smoke becomes trapped within the boundary layer," the National Weather Service warned.

CZU LIGHTNING COMPLEX FIRES

• Evacuation Info, Burn Zone Map, Fast Facts
• Evacuation Map
• Google Map of Fire Area
• Wildfire Shelter Map, Information

The region has been under a Spare the Air alert since last Tuesday due to wildfire smoke from the lightning-sparked fires started on August 16.

Visibility from a camera from Berkeley's Hall of Science revealed a mass of smoke and fog and not its normal view of San Francisco across the Bay.

Bay Area air quality officials said a Spare the Air Alert has been extended through Sunday.

"Air quality is expected to be unhealthy in portions of the Bay Area due to continued smoke impacts from wildfires," officials said in a social media post.

The following online resources are available to check current air quality where you live and find out when it's healthy to resume normal activities outside.

• Bay Area Air Quality Management District
• BAAQMD Current Air Quality
• EPA AirNow
• Purple Air – A good way to track trends in air quality related to particulate matter, but the sensors may register higher numbers than the air actual air quality.

The CZU Complex was burning in the timber-rich Santa Cruz Mountains, creating a billowing layer of thick wood smoke. By Friday morning, the fire complex had grown to 82,540 acres with 26 percent containment. At least 554 homes have been destroyed.

Many local residents took to social media to share comments and photos of the gloom.

Since dozens of wildfires were ignited by dry lighting strike almost two weeks ago, the three largest complex of fires -- the CZU Lightning Complex, the LNU Lightning Complex, the SCU Lightning Complex -- had burned near 830,000 acres or 1297 square miles in the San Francisco Bay Area by Friday morning.