Mountain Weather Forecast

Weather Synopsis for Sunday night through Friday

A significant winter storm and major wind event continue to impact the region. While the cold front passed Sunday morning, the vertically stacked low-pressure centers will move across southern British Columbia this evening, bringing our region strong to extreme westerly alpine winds for most areas south of Mt. Baker and Washington Pass. The flow pattern combined with steep decreases in temperature with height should continue to produce heavy mountain snowfall both west and east of the Cascade Crest. The heaviest snowfall overnight should focus on the south and central Washington Cascades from Paradise to just south of Mt. Baker where we expect around another foot of snow could fall, with the highest totals likely in the heavy showers and convergence bands. Convergence should shift southward this evening from the Mountain Loop, potentially reaching near or just north of Snoqualmie Pass by morning at which time, gradually lowering snow levels should bring snowfall down to the Cascades foothills. Winds gradually ease late Sunday night through Monday but should still be strong in many alpine areas Monday morning. Expect some light lingering snowfall and weak convergence across the west slopes and passes of the Cascades (up to several inches of snow possible), but further east and in the Olympics, sunshine will make appearances.

A ridge building offshore cuts off the precipitation by Monday night as it moves over the region. High clouds should move over the region Monday night as the next weak system approaches with clouds increasing Tuesday morning and eventually bringing some light rain and snow. The atmosphere warms significantly on Tuesday so expect light rain up to 2000-4000 ft where it falls in the Olympics and Mt. Baker area.