Hazy skies over San Francisco and other Bay Area cities today are being caused by smoke drifting north and west from two wildfires in the Central Valley: the Mineral Fire, which has been burning near the community of Coalinga in Fresno County, and the closer Coyote Fire, which has been burning since Wednesday near the community of Panoche in San Benito County.

The combined smoke from the two fires has not been significantly impacting ground-level air quality in the Bay Area, though that may change. As KPIX reports via the Bay Area Air Quality Management District, an air quality advisory has been issued due to the Mineral Fire but the district says that "smoke will likely remain aloft" and air quality is supposed to remain at normal levels for most areas.

A radar simulation from the National Weather Service shows us how the onshore air flow should clear the smoke toward the east by Thursday evening, though it looks like the East Bay hills could still be impacted well into the evening.

The Mineral Fire began Monday just before 5 p.m. near Hwy 198 and South Coalinga Mineral Springs Road, west of Coalinga, and as of Thursday morning it had grown to 16,500 acres and was still only 20-percent contained. According to CalFire the fire is "burning in difficult to access areas and in fuels with no fire history," and "Containment efforts will be hampered due to extreme fire behavior which includes rapid uphill and wind driven runs." The cause of the fire remains under investigation.

The Coyote Fire in San Benito County broke out on Wednesday afternoon, and it has grown to 1,400 acres as of this morning. It is now 50-percent contained.