Original post (Friday, Aug. 23): The fire racing through forests on the western boundary of Yosemite National Park is causing serious air-quality issues around the Lake Tahoe basin and in Washoe County, Nev., which includes Reno, and in the Nevada state capital, Carson City. NOAA satellite photographs (above) show massive smoke plumes spreading northeast from the Rim Fire, which has burned 105,000 acres since it ignited earlier this week due to as-yet-undetermined causes.

The Washoe County Air Quality Management District issued an advisory for air with high levels of particulate and ozone pollution. The agency rates the air today as "unhealthy" for all groups—both the general population as well as sensitive groups such as children, seniors, and those who suffer from long-term heart and lung conditions. Unhealthy air conditions are expected to last at least through the weekend.

Earlier this week, the American Fire, burning in heavily forested hills northeast of Auburn, also spread smoke across the Tahoe-Reno area. That fire has burned about 20,000 acres and is 66 percent contained.

RenoReno

Tesla Breaks Ground on 'Potential' Nevada Site for Battery Factory

Rim Fire Fallout: Smoke Still Spreads from Blaze to Lake Tahoe, Reno and Beyond