It's been a temperature roller coaster recently. After a prolonged period of arctic air, some areas saw a tremendous increase in temperatures with highs in the 40s. This warmup was short-lived. The next shot of arctic air will be short lived as well. Through the course of the weekend, high pressure will build in and eventually allow for a chinook wind to warm up much of the state. The arctic boundary will work south to start off the weekend. Temperatures will again drop into the 0s and 10s for most of the state on Saturday. Saturday night will be cold with lows dropping below 0, but the larger pattern change and some warming will begin on Sunday. High pressure will move in clearing out the skies and the snow, and temperatures will warm for most locations in the mountains and the plains. Highs will climb into the 20s and 30s across the plains. However, valley locations like Helena, Lincoln and Townsend will likely become inverted with cold air trapped in these lower elevation. Highs in these places on Sunday and early next week should hold in the 10s and 20s. As we get further into next week, the valleys and plains will continue to diverge with regards to temperature. Most of next week looks mild and quiet with strong wind over the plains. The valleys of western Montana should stay calm but cold with this being the heart of inversion season. Overall this quiet, mild break that often is called a January Thaw will likely continue through next weekend. For the final week of January, colder temperatures with snow will return.
Have a great weekend.