A week of high pressure over the top of the valleys of Western Montana has caused fog, freezing fog and hazy conditions.

The air quality has deteriorated enough that Missoula (the hub of 5 valleys)has issued daily Stage 1 and Stage 2 Air Quality Alerts.

The Bitterroot Valley has fared a little better, with hourly particulate count only reaching the "Unhealthy for Sensitive Groups" category for a few hours each day, but the cumulative 8-hour and 24-hour average readings have reached the "Unhealthy" levels.

Weather forecasters are expecting wind and some snow Thursday, January 24, and again this weekend to "clear the air."