As of Wednesday afternoon, Missoula air quality is once again officially unhealthy for sensitive groups.

Air Quality Specialist with the Missoula City County Health Department Sara Coefield says the large plumes of smoke from fires burning to the southwest are rising high into the atmosphere where prevailing winds are depositing them right into the Bitterroot and Missoula valleys.

The Mustang Complex and the Powell Complex fires are the major contributors to the smoky conditions.

Coefield says by Thursday afternoon and evening, a weather front with easterly winds may help to alleviate the unhealthy conditions.

Air Quality Specialist Sara Coefield