High pressure will build into western Montana the rest of the week, bringing a tranquil weather pattern to the northern Rockies.
We will be on the northeast side of the clockwise rotation, which means we will have a moist northwest flow bringing partly to mostly cloudy skies to the area through Wednesday.
As the high moves more directly overhead, southwest Montana will see slightly milder weather later this weekend into the weekend. Sunshine will occur Thursday through the weekend in the Butte and Bozeman areas. Lows in the single digits and 10s with highs in the 30s.
Cold air will become trapped in the valleys west of the divide. This will keep highs in the 20s in the Missoula and Kalispell areas Thursday through the weekend. Also, valley inversions will strengthen, and that means the possibility of fog. Fog and low stratus clouds may stick around all day, especially in the Mission and Flathead Valleys.
Mixing will diminish the fog early next week.