The sun can pack a punch this time of year. Be aware of signs of deteriorating stability such as snow pin-wheeling down slopes or small point-release avalanching below cliffs.
Weather Forecast
WEDNESDAY: Mix of sun and cloud / Light to moderate southwesterly ridgetop winds / Alpine high of -7 with an above freezing layer of air between 1400-1600 m in some areas of the region.THURSDAY: Mostly cloudy / Light to moderate southwesterly ridgetop winds / Alpine high of -4 with an above freezing layer of air between 1100-1600 m in some areas of the region.FRIDAY: Mix of sun and cloud / Light westerly ridgetop winds / Freezing level rising to around 1600m.
Avalanche Summary
No new avalanches have been reported in this region.
Snowpack Summary
Accumulated storm snow from last week totals 25-40cm. This new snow covers previously wind-scoured, westerly slopes and old hard and soft wind slabs on leeward, easterly alpine and treeline slopes. Beneath these old wind slabs lies a well-settled mid-pack. The lower snowpack is generally weak with two primary concerns that are widespread:A weak layer from mid-December composed of facets, crusts, and surface hoar that is 100-150 cm deep.A rain crust with sugary facets buried in late November near the bottom of the snowpack.
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.