The northwestern U.S. and southern British Columbia are bracing for a turbulent December as a series of storms are expected to bring heavy rain, snow, and a mix of wintry conditions. Montana and the northern Plains anticipate snowfall over the weekend, while the Cascades region will experience rain and mixed precipitation. Forecasters are particularly concerned about the potential for atmospheric rivers to unleash 6–12 inches of rain next week, which could lead to significant flooding, mudslides, and an elevated risk of avalanches.