An AIR STAGNATION ADVISORY remains in effect for some valley locations of western Montana.
A dominant ridge of high pressure is not moving, so what you've seen over the last few days is what you will see over the next few days. The jet stream has lifted well north into Canada as a monster ridge of high pressure stretches across western North America. This pattern will persist through this weekend and into next week. While skies will be clear for most of the state throughout the period, other weather conditions will differ. The valley of western Montana will have inversions which will trap colder air with calm wind conditions. While these inversions have existed for days, the only location with "moderate" air quality is the Seeley Lake area. There also has been some fog near Ronan and St. Ignatius. Meanwhile the plains and higher elevations will continue to be breezy with milder temperatures. Overnight lows will also be much colder in the valleys than the plains. Changes are likely toward the end next week. The ridge of high pressure will break down by midweek and snow is possible for the second weekend of December.
Have a great day!
Curtis Grevenitz
Chief Meteorologist
