MISSOULA — Monday will start dry with a bit of sunshine during the early morning. Clouds will then quickly increase by mid morning with scattered rain showers developing by late afternoon and evening. Showers will be most widespread in west-central and southwest Montana. High temperatures Monday will only be in the 50's to low 60's.
Tuesday night into Wednesday is looking very interesting as a low pressure system moves into the northern Rockies and targets specifically west-central and southwest Montana. As the low pressure moves through, it will bring a round of cold air into the region.
Snow levels look to drop to around 4,500 - 5,000 ft. by Wednesday morning. Areas around Deer Lodge, Butte, Philipsburg, Georgetown Lake, Homestake, MacDonald and Lost Trail Passes will have a chance to see potentially heavy snow during this time. If the current track holds steady, driving over Homestake and MacDonald Passes may become very difficult due to snow. It's not out of the question for over a foot of snow to fall above 6,000 ft. during this time.
For the valleys of western Montana, expect cool and wet conditions Tuesday into Wednesday with scattered rain showers and temperatures in the 50's to low 60's.
Temperatures will start to warm Thursday and Friday. A few scattered rain showers will remain in the forecast as well. Highs will be in the low to mid 60's Thursday and upper 60's to low 70's Friday.
High pressure will build in for the weekend leading to sunshine and much warmer weather with temperatures returning to the 80's by Sunday.