Weather Synopsis for Monday & Tuesday

The last in a series of winter storms impacts the region Monday and Tuesday. Post-frontal showers on SW flow became scattered on Monday morning but continued for some parts of the west slopes of the Cascades. These showers generally continue to diminish through the morning hours. A strong frontal system associated with a pronounced offshore trough approaches the coast in the afternoon, spreading increasing light and, in some cases, moderate rain and snow throughout the region. Snow levels rise from around 2000 ft in the morning to 2500-3500 ft. Ridgeline winds shift more to the SSW and generally increase but remain in the light to moderate range.

The front arrives Monday evening with moderate to heavy rain and snow, moderate to occasionally strong SSW ridgeline winds, and a touch of warming. Light E flow through the passes may insulate the Pass level from the subtle warming, but expect snow levels to rise above pass level following the late evening frontal passage and before temperatures cool. Moderate snow showers continue through Tuesday for the west slopes of the Cascades. Models indicate the potential for locally heavy snowfall in a convergence band forming around Mt Baker early Tuesday and dropping southward as the day progresses. This band could drop as far southward as Stevens Pass by the end of the day. Snow levels lower from around 3000 to 2500 ft while winds generally remain steady or decrease in the light to moderate range, accelerating east of the Cascades Crest.