A combo of lingering wind slabs and weak basal layers affects the alpine while rugged early season conditions prevail at lower elevations.
Weather Forecast
Saturday night: Mainly cloudy with light west winds.Sunday: Cloudy with sunny periods. Light southwest winds. Alpine high temperatures around -5.Monday: Cloudy with scattered flurries bringing a trace to 5 cm of new snow. Wet flurries at lower elevations. Mainly light southwest winds, increasing overnight. Alpine high temperatures around -1 as freezing levels rise to about 1600 metres.Tuesday: Cloudy with continuing flurries bringing about 5 cm of new snow. Wet flurries at lower elevations. Light to moderate southwest winds. Alpine high temperatures around -1 with freezing levels to 1700 metres.
Avalanche Summary
Skiers and explosives have recently triggered small wind slabs in cross-loaded and lee terrain features at treeline and alpine elevations. Earlier in the month, a natural avalanche cycle took place over the late October crust/facet combination. Be aware of the continued possibility for smaller avalanches to 'step down' or even initiate at this deeper layer. It exists primarily in the alpine.
Snowpack Summary
Light snowfall over Thursday and Friday buried a widespread layer of weak, feathery surface hoar crystals with about 5-10 cm of new snow. On steeper solar aspects, this surface hoar layer may instead exist as a thin sun crust below the storm snow. Reports from several points in the region show this variable layer sitting above a layer of recently reactive wind slab. This wind slab layer overlies yet another widespread layer of surface hoar from mid-November, now found about 20-40 cm deep. A final, prominent feature of the snowpack is a combination of a melt-freeze crust and underlying sugary, faceted snow found around the base of the snowpack. Avalanches have been triggered where there is a slab above this crust.
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.