Mountain Weather Forecast

Weather Synopsis

An upper-level trough will pass inland this afternoon and scattered snow showers currently from about Stevens Pass and south will continue to wane through Thursday evening.  For the first part of tonight, we'll see a mix of partly to mostly cloudy skies south of Snoqualmie Pass and mostly clear conditions to the north. High clouds from the next approaching system should filter in late tonight and increase tomorrow morning with cloudy conditions forecast for all areas by mid-morning Friday. 

A frontal system will slowly approach the coast on Friday, spreading snow and wind over the Olympic peninsula. The heaviest snow is likeliest for the eastern and southern parts of the Olympic range, with lower amounts likely for the Hurricane Ridge area. A warm frontal feature will try to push further inland to the Cascades Friday afternoon, but it's unclear how much or if any moisture will actually arrive. What is clearer is that with high pressure over southern British Columbia and an approaching low pressure system, offshore flow and easterly winds will strengthen during the day tomorrow, especially through the Cascade Passes.  The low complex will begin to cut-off and drop-south along the Pacific coastline Friday night, but not before additional warm frontal moisture pushes over the Cascades.  Snowfall amounts generally look like except for portions of the Olympic peninsula.  

We should see a drying trend on Saturday as the low pulls further south.  However, counter-clockwise flow around the low pressure system will combine forces with offshore flow to create a windy easterly pattern for many areas beginning Saturday afternoon. There will be a slight warming trend for areas well west of the Cascade crest on Saturday and a continuation of colder temperatures elsewhere.