Avalanche Forecast
Regions: Stevens Pass.
Some strong NE winds Friday night and Saturday morning, may have formed Isolated but shallow wind slabs mainly on westerly aspects near and above treeline.
Detailed Forecast
Fair and cool conditions are expected Sunday with light winds and gradually increasing high clouds. This should maintain mostly stable and firm surface or near surface snow layers. Watch for some local areas where potentially more new snow may have been deposited from late last week, especially near the crest.
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
February began with warm and wet weather, followed by fair weather through mid-February, leading to generally thick surface crusts, as well as further deterioration of the snow cover below treeline.Â
After some light snow accumulations midweek along the west slopes, 6-10 inches of new snow accumulated Thursday night and Friday above 4000 ft from Snoqualmie Pass and south, including Crystal Mt and Mt. Rainier. Significantly less new snow was received along the west slopes near and including Stevens Pass northward to Mt Baker, where generally an inch or less of new snow fell. Â
There was not enough new snow in these zones to cause much increase in danger, however, professional NWAC observer Jeremy Allyn was at Paradise on Friday and found 25 cm (10 in.)  of new snow bonding well to previous snowfall received midweek and layering with a favorable density profile. By mid-day Friday, east winds were beginning significant snow transport near treeline and fresh wind slabs were developing on westerly aspects as evidenced in this short video clip from Jeremy on our Instagram account.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.
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: North, South, South West, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 1 - 1