Avalanche Forecast

Decreasing winds, decreasing clouds and mostly sunny weather should be seen Saturday. Warmer temperatures should be seen by Saturday afternoon.

The main concern should be any new wind slab built on lee slopes in the alpine and perhaps in the near treeline by the front on Friday. The best chance for this new wind slab should be in the north Cascades where new snowfall should have be heaviest. This wind slab should be small and shallow in most other areas.

Minor wet loose avalanches might also be possible by Saturday afternoon on solar aspects. Again the best chance for this should be in the north Cascades where snowfall should be heaviest. This is less likely in most other areas.

Shallow amounts of stable snow that generally bond well to previous snow should be seen in most areas.

Warm wet weather 13-14 December followed by dry weather and high freezing levels helped to form crust layers and have generally helped stabilize hoar frost and faceted snow from early December.

A series of fronts and warming temperatures from about 20-23 December mainly caused 1-2 feet of heavy snow in the alpine and some very wet snow and rain near and below treeline. On 20 and 21 December the Mt Baker ski patrol reported widespread 4-14 inch sensitive ski triggered wind slab. Then on 22 December a professional guide reported a large wet slab avalanche running from Chair Peak near Snoqualmie Pass along with other signs of wet snow instability.

Dry and generally mild weather occurred Tuesday through this morning.  

Reports from NWAC observers, DOT personnel and TAY folks the past couple days include stable surface crusts at Stevens, minor wet loose triggered avalanches on solar aspects in the alpine at Snoqualmie, and also some old powder near treeline or in the alpine on non-solar aspects at Snoqualmie. DOT personnel on a 5000' northeast aspect at Alpental found a generally stable and well bonded upper snowpack made up of crusts and rounded melt forms except for a hard to trigger but high quality shear on a softer melt form layer about 2 feet below the surface.

A front is crossing the Northwest on Friday. This will cause southwest winds to shift to the northwest with rain changing to a little snow at the higher elevations with cooling temperatures.

The avalanche danger will continue to be low at the lower elevations due to our ongoing lower than normal snowpack. Non-avalanche hazards such as exposed rocks, creeks, and icy surfaces exist and present a travel challenge.