MISSOULA — Air Stagnation Advisories are in effect for the Missoula and Bitterroot valleys after a lack of mixing air has allowed inversions to form and for air to become stagnate in those valleys under the inversion layer.
Keep in mind pollutants such as car exhaust and smoke will be trapped near the surface through Sunday morning, so air quality will fluctuate during these days.
Otherwise, temperatures in valleys stay cooler during overnight hours- dropping to the teens and single digits in most areas.
Daytime temperatures will rise to the mid to low 30s in the northwest and west-central valleys while the Bitterroot Valley will be in the mid to upper 30s through the end of the week.
We keep dry (minus the morning freezing fog) through the week and most of the weekend.
Freezing fog in early morning hours will continue to develop under these stable conditions, and slick spots on roadways are possible.
Snow returns for the end of the weekend through early next week.
During this time, highs will drop to the 20s and low 30s, so it will be cool enough at all elevations for snow to accumulate through the first days of February.