MISSOULA — Mountain snow and valley rain showers move in Tuesday as a weak "Atmospheric River" sets up. Precipitation will primarily fall as rain in the valleys, however, a few valley locations in northwest Montana may see a brief hit of snow this morning. Snow will be heavy at times in the mountains today. Difficult travel is expected over Lookout, Lolo, Lost Trail and Marias Passes.
With the steady precipitation, mild temperatures and gusty winds expected today, an "Avalanche Watch" has been issued for the mountain ranges along the Montana/Idaho border in northwest Montana and north central Idaho. Back country travel is not advised in Tuesday.
By this afternoon, showers will become more isolated, however, more intense in nature. Under the stronger showers, gusty winds up to 40 mph along with graupel will be possible. With the thawing ground and wet soil, the stronger wind gusts could be enough to knock down trees.
Lightly scattered rain and snow showers stick around Wednesday with highs in the low to mid 40s.
After a dry day Thursday, showery conditions are expected to return Friday and continue into the weekend. None of the systems appear to be strong as these small weather features will keep it breezy and showery. Most of these systems will cause rain showers at the lower elevations and be a nuisance at higher elevations at worse.