SAN FRANCISCO (CBS SF) – The Bay Area Air Quality Management District on Friday extended its air quality advisory due to smoke from ongoing wildfires, announcing that the advisory would remain in effect through Sunday.

The organization tweeted about the extension of the advisory late Friday morning.

Officials said smoke is expected to remain mostly aloft, causing hazy skies in much of the region. But intermittent periods of smoke mixing to the surface is possible at higher elevations in the North Bay and the East Bay.

The agency is not issuing a Spare the Air alert, as air quality is not expected to exceed the federal health standard.

Residents are being urged to stay indoors when the smell of smoke is present and those impacted by smoke should set air conditioners and car vents to recirculated air. The elderly, children and those with respiratory illnesses are particularly vulnerable.

Additional information can be found at the Bay Area Air Quality Management District website.

Numerous wildfires continue to rage in the California and the west, including the Dixie Fire, which has become the largest wildfire currently burning in the United States. As of Thursday morning, the fire burning in the Northern Sierra Nevada has burned 510,227 acres and is 30% contained.