Another Spare the Air alert banning wood fires has been called for Friday in the Bay Area as a light rainstorm failed to clear the air as much as hoped.
The no-burn alert for Friday is the second this week and the ninth issued by the Bay Area Air Quality Management District since Nov. 1.
Alerts are issued when unhealthy air is predicted due to stagnant weather conditions that trap smoke and fine particles near the ground. On those days, the air district bans wood fires in fireplaces, fire inserts, stoves or outdoor fire pits.
An alert also was in effect Wednesday despite rain, which often comes with ocean winds that sweep pollution out of the nine-county air basin.
But this weather system was weak and relatively warm, failing to stir up the air enough. Fine particle pollution readings violated the federal public health standard on Wednesday in Oakland, San Francisco, Concord, Livermore, and San Pablo, district officials said.
The agency had forecast high pollution readings for Wednesday, but was surprised to see pollution levels as high as they were, said Jack Broadbent, the air district executive officer. "Unfortunately, we are expecting unhealthy conditions again on Friday."
First-time burn violators must pay a $100 fine or take a smoke health education class. Second time violators can be fined $500.
Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff