The Northern Sierra Air Quality Management District is issuing an air quality health advisory for September 14 and 15, 2015. The tremendous amount of smoke from the Butte Fire, the Valley Fire and the Rough Fire have caused high levels of particulate matter throughout the air district. Smoke concentrations are likely to reach the Unhealthy or Unhealthy for Sensitive Groups range off and on over the next couple days. Some precipitation is forecast throughout the air district which may decrease particulate levels. Increasing winds expected later in the day on September 14 may help to clear the air, as well.