Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely.
Regions
Northwest Inland.
Confidence
Poor - Due to limited field observations for the entire period
Weather Forecast
Saturday: The effects of a weak ridge of high pressure will be brief. Generally broken skies with little to no precipitation for most of the day with a warm front pushing in for the late afternoon. Light amounts of snow are expected for the overnight period into Sunday. Winds northwest 20 km/h for the daytime period changing to west 30-50km/h in the late afternoon. Alpine temperatures -8. Sunday: Light to moderate precipitation throughout the day with strong northwesterly winds. Alpine temperatures -4 degrees. Monday: Continued light to moderate precipitation with southwesterly winds 30km/h. Freezing levels expected at 800m with alpine temperatures -6 degrees.
Avalanche Summary
There is no new avalanche activity to report at this time. If you have been traveling in the backcountry recently, send us your observations. Every bit of information helps us to produce a better product. Email us at [email protected]
Snowpack Summary
Wind slab instabilities exist in the upper snowpack at treeline and in the alpine. Treeline snow depths range between 90-125 cm. Snow depths in the alpine are highly variable with deep wind drifts and heavily scoured slopes in exposed areas. A layer of small surface hoar crystals exists at tree-line in isolated sheltered areas. This is most likely buried down 15-20 cm under recent storm snow. A weak layer of facets sitting on a crust exists near the base of the snowpack down 80-130 cm. Test results on this layer earlier this week produced hard, sudden results.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.