Mountain Weather Forecast

Weather Synopsis

The long-awaited return to winter is on the doorstep with a strong frontal system and cold upper trough on tap for the weekend. First, we'll see a mix of low and high clouds over the north Cascades give way to overcast skies later this evening as high clouds stream in from the north.  Mostly clear skies for areas further south should also become overcast before daybreak.  

A E-W oriented frontal system will drop south through Washington state on Saturday afternoon with a cold upper level trough trailing Saturday night.  Rain and snow will begin for the northwest Cascades in the morning and slowly spread south during the day. Westerly winds will quickly ramp up in advance of the front, becoming strong in most areas and extreme east of the Cascade crest by Saturday afternoon.  Moderate snowfall will fall in the Mt Baker area Saturday afternoon while the rest of the region waits until late Saturday afternoon or night. Snow levels will hover around 3000-3500' during the day, and Snoqualmie Pass may mix with rain at Pass level initially. 

Snow levels will fall Saturday evening and overnight with snow showers and blustery westerly winds. A Puget Sound Convergence Zone should affect the Mt Loop Hwy, Stevens Pass and Snoqualmie Pass areas with the heaviest snowfall. Stevens Pass in particular looks poised to see a period of heavy snowfall rates through early Sunday morning. 

The PSCZ should shift south towards Snoqualmie Pass Sunday morning with snow showers becoming more scattered elsewhere during the day. The exception will be Mt. Hood where both the wind and snow showers will continue to pile up fresh accumulations. 8-20" through Sunday afternoon is likely along much of the west slopes of the Cascades and Mt Hood while snow amounts will taper off rapidly further east of the Cascade crest.