Avalanche Forecast
Regions: Snoqualmie Pass.
Shallow new wind slabs potentially formed on a variety of aspects may be found above treeline Friday.
Detailed Forecast
Generally light snowfall amounts are expected Thursday night and Friday.  However, winds should increase and back to SE Friday morning and then to ENE Friday afternoon, potentially creating shallow new wind slab and cross-loading slopes mainly above treeline. Â
Currently there is not enough new snow forecast to increase the avalanche risk at lower elevations. If the forecast goes awry, make sure to change your travel plans accordingly.Â
Due to the low snowpack, especially below treeline, watch for terrain hazards such as open creeks, partially covered rocks and vegetation. Many areas below treeline do not have enough snow (new or existing) to pose an avalanche hazard.Â
Snowpack Discussion
Since the warm and wet start to February, fair weather through mid-February has led to generally thick surface crusts, as well as further deterioration of the snow cover below treeline.Â
A few weather disturbances passed through a week ago, bringing a welcome few inches of snow near and above treeline. Winds veered to the east or northeast last Saturday, causing some new wind slab formation on non-traditional more westerly to southerly aspects mainly above treeline. A few reports of ski-triggered shallow wind slabs were reported from the west slopes over the weekend, generally found above treeline. Â
Generally 1 to 3 inches of snow accumulated at NWAC sites Wednesday night through Thursday afternoon above about 4000 ft with rising snow levels in the afternoon. No significant avalanche problems were expected or reported.  Â
The mid and lower snowpack west of the crest snow consists of layers of stable consolidated rounded grains or melt forms and crusts from multiple warm periods this winter.
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Avalanche Problems
Wind Slabs
Release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..
Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.
Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1