Mountain Weather Forecast

Weather Synopsis

5 pm Update: Increased Wednesday night 5000' temperatures

Drippy warm frontal precipitation will continue to taper down this afternoon and early evening. This first round of precipitation brought only a few inches of snow near and west of the Cascade crest, the west-side of the Olympics and Mt Hood with very light accumulations elsewhere. Snow levels have risen into the 3000-4000' range over the Washington Cascades and will more or less stay there overnight as we wait for the next system.  Snow levels are higher down in the Mt Hood region. 

Very light warm frontal precipitation will linger over the northwest Cascades through the early morning hours with dry but mostly cloudy conditions expected elsewhere. With milder air over the region, there isn't much cooling as you climb higher; expect overnight lows to stick near freezing in most locations and elevations.

 A quick moving frontal system approaching from the NW will sweep through the Cascades mid-afternoon on Friday.  This system will bring moderate snow to the Mt Baker and Olympic area beginning in the late morning hours. Areas south of Snoqualmie Pass will have to wait until the frontal passage in the afternoon for a burst of rain and snow.  Snow levels will not be particularly cold with the system, hovering in the 3000-4000' range. Look for very strong westerly winds to develop out ahead and with the frontal passage Friday afternoon.  

A trailing upper level trough will quickly pass overhead Friday night with post-frontal showers heaviest in the evening. Strong westerly ridgeline winds will continue through Saturday morning. Shower activity will begin to wane later Friday evening, except where a Puget Sound Convergence Zone (PSCZ) forms in the Skagit/Snohomish/northern King County corridor. The PSCZ could deliver a nice shot of additional snow above 3000' from the Mountain Loop Hwy to Stevens Pass Friday night. Strong westerly ridgeline winds will continue through Saturday morning.

A strong upper level ridge will build offshore. Saturday will be a transition day towards milder and drier weather.  Low clouds will be slow to clear along the west slopes of the Cascades with a few drips possible between Stevens/Snoqualmie Passes in the morning. An overall clearing trend with rising freezing levels will take hold Saturday afternoon and evening.