Bay Area residents can blame the current weather pattern for Thursday’s poor air quality. NBC Bay Area Meteorologist Kari Hall said an inversion layer is trapping pollution at the ground level. “High pressure causes the air to sink,” Hall explained. “It creates basically a cap or a lid over the Bay Area, and there’s not much of a wind to help mix things out. Then you add on top of that some cold air, it draws everything down to the surface.” The Bay Area Air District said offshore winds may also transport pollution from the Central Valley into the Bay Area. A Spare the Air alert that bans the burning of wood will be in effect through Saturday in the Bay Area because of a forecast for high levels of pollution, regional air quality officials said. The air district had previously issued an alert for Thursday and extended it through Saturday because of cold temperatures and offshore winds that have led to high levels of pollution in the region. On Spare the Air days, it is illegal for residents and businesses to use their fireplaces, wood stoves, pellet stoves, outdoor fire pits, or other wood-burning devices. There are exemptions, such as for homes without permanently installed heating, according to the air district. People found to have violated the wood burning ban will be encouraged to take a wood smoke awareness course if it is their first offense. Violators who don’t take the course will receive a $100 ticket, and subsequent violations will lead to higher fines. Wood smoke exposure has been linked to respiratory illnesses and an increased risk of heart attacks and some types of cancer, and is particularly harmful for children, older adults, and those with pre-existing respiratory conditions, air district officials said. You can check the air quality in your neighborhood by visiting nbcbayarea.com/airquality. ...read more read less