Via National Weather Service Missoula, MT: A steady stream of precipitation will punch into the Northern Rockies through the day Wednesday, causing moderate to heavy rainfall to impact north central Idaho and western Montana. Several inches of rain will accumulate during this time, causing various impacts:
Rock/mud flows and excessive runoff over roadways, in addition to the potential for clogged culverts resulting in localized minor flooding.
Along with mild valley weather, strong winds will be common throughout the week. Valley winds will be in the 20 to 30 mph range (especially Wednesday through Thursday, when winds will be strongest), with gusts to 40 mph possible in localized areas. Winds in higher terrain could reach up to 60 mph, with stronger gusts possible. In addition, snow levels will rise through the week, reaching roughly 7,000 ft by Wednesday morning. Moderate to heavy snow will fall throughout the week, but remain in the highest terrain. As a result, backcountry conditions will be raw, thanks to the combination of precipitation and strong winds.