Avalanche Forecast

A weak frontal system passing through the Cascades early Wednesday morning should bring light amounts of new snow above 3500 feet. The exception may be in and around an area of convergence in the central Cascades likely between Stevens and Snoqualmie Passes Wednesday afternoon. Brisk westerly winds Wednesday afternoon should also build fresh wind slabs on lee easterly aspects.

New storm and wind slabs may locally become a concern in areas that experience intense snowfall rates Wednesday. Watch for potentially increasing avalanche danger in the afternoon and be prepared to change your plans if conditions warrant.    

In much of the below treeline band there is not enough snow yet for avalanches.  Avalanche problems should be limited to the upper part of this elevation band.

Weather Discussion for the Cascade West Slopes

After a stormy Thanksgiving weekend which especially hammered the Mt. Baker area, a frontal passage Sunday night was followed by a period of NW flow that dropped 4-12 inches of snow along the west slopes of the Cascades through Monday morning. A few additional inches accumulated during the day Monday with light to moderate showers and snow levels around 3500-4000 feet. Tuesday was a break between weather systems.  

Recent Reports for the Cascade West Slopes

NWAC pro observer Lee Lazzara was touring up to about 5000 feet near the Mt Baker ski area on Sunday. Overall the snowpack was found to be generally right side up with less dense snow nearer the surface and with no alarming layers.    

Mt. Baker pro-patrol generally triggered 6-8" storm slabs during their Monday AM control work, but one larger 12" slab released on a SE aspect @ 5500 ft during control, breaking 150 feet across and running several hundred vertical feet.  

Alpental pro-patrol found a homogeneous 2 ft of recent storm snow on top of older snow at the top of their hill with an average snowdepth of 3 ft (1 m) above 5000 ft although snowdepths varied widely depending on wind affect. Low quality shears were found in snowpack tests and there were no layers of concern within the new storm snow.  

DOT professionals were at Chinook Pass Monday and found a well bonded snowpack with generally dense surface snow.  

In general the below tree-line elevation band has plenty of terrain anchors and offers lower avalanche potential outside of the Mt. Baker zone. The near and above treeline bands have been filling in throughout the west slopes of the Cascades but are the most shallow in the Pass zones including Stevens, Snoqualmie and White.