A Special Public Avalanche Warning is in effect for the weekend. Stay cautious and be conservative in your terrain selection.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Increasing cloud, moderate west winds and some light flurries are expected overnight Thursday. On Friday, cloudy skies with light snow amounts near 5 cm. Alpine temperatures near -10. A brief lull in the pattern for Saturday as a second Pacific low deepens off the coast. This low could bring moderate amounts of snow Sunday afternoon and overnight into Monday, however; confidence is poor with timing and precipitation amounts due to model discrepancies.
Avalanche Summary
No new avalanches have been reported.
Snowpack Summary
Snow surfaces are variable with northerly, wind exposed aspects showing firm wind press or scoured exposed crust, and more sheltered locations have up to 30 cm of light, low density, faceted snow. In the alpine and at treeline, strong northerly winds have transported this snow into stiff and reactive wind slabs on opposite slopes. Up to 70 cm below the surface (more in wind affected areas) you will likely find a hard, thick crust which formed mid-December. At higher elevations this crust has facets (sugary) snow above it and well-preserved surface hoar up to 10 mm in size in sheltered locations at treeline and below. Where the crust exists, it may be bridging triggers from penetrating to deeper persistent weaknesses. However, on high alpine slopes above where the rain crust formed, or in areas where rain didn't occur, deeply buried facets may still be susceptible to triggering, especially in thinner snowpack areas.
Problems
Wind Slabs
Wind Slab avalanches are the 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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.