🏔️ Valley Cold Pools & Fog Building Early This Week 🏔️ We are watching a classic winter setup unfold across the Northern Rockies. A ridge of high pressure is building over the region, which acts like a "lid" on our atmosphere. While mountain peaks may enjoy some warming, the cold air will become trapped on the valley floors. What This Means for You: Freezing Fog: Increasing coverage of fog and low clouds in the valleys of Western Montana and North-Central Idaho early this week. Slick Travel: Freezing fog can leave a thin, icy glaze on roads and overpasses—even when it isn't "snowing." Temperature Trends: Expect cold mornings and very little warming during the day as the ridge keeps the "cold pools" locked in place. The ridge is expected to hold through at least Thursday, though exactly when it breaks down remains uncertain. 🚗 Traveling? Check visibility and road conditions before you go: weather.gov/mso