MISSOULA - Generally, a westerly flow will continue to bring 'off and on' mountain snow and valley rain showers running into Wednesday before a larger, more complex closed low pressure system moves into the region.
Without the steering of the jet stream, this system will take its time moving through the area with the exact track still a bit unclear at this point. It will, though, usher in a southwesterly flow at first with highs in the 50s for Wednesday and increasing showers by the evening (maybe even a rumble or two of thunder!).
By Thursday, the cold air associated with this low will move into the region with snow levels now dropping to around 3,000' causing a good spring snow in many higher elevation valleys. The valley snow in western Montana will vary greatly due to several factors including warming ground temps and a higher sun angle at this point in time.
Right now, we have Winter Storm Watches out from early Thursday to late Thursday for the Bitterroot/Sapphire Mountains and the Butte/Blackfoot & Potomac/Seeley Lake Regions. Elevations above 5,500' will see anywhere from 6"-12" (including MacDonald, Homestake, Lost Trail & Lolo Passes) with valleys down to 3,000' picking up 2"-6" (this would include Georgetown Lake, Butte, Anaconda, Philipsburg, Seeley Lake, etc.). Valleys that do see accumulation will see a heavy, wet nature of snow which will likely build up on trees, creating potential tree damage and power outages.
Precipitation looks to continue into Friday late morning with a mostly cloudy afternoon on tap and highs in the upper 40s.
As of now, the upcoming weekend will start of sunny with mid 50s to around 60° and end partly sunny with upper 50s to mid 60s continuing into early next week.
