The primary concern is persistent weak layers lurking in the snowpack. These types of problems take time to heal, and are best managed with patience and conservative terrain choices.
Summary
Confidence
Moderate -
Weather Forecast
SATURDAY NIGHT: Scattered flurries with localized accumulations of 2-8 cm, moderate wind from the south, alpine temperatures around -10 C.SUNDAY: Isolated flurries with localized accumulations of 2-4 cm, light wind with moderate gusts from the south, alpine high temperatures around -6 C.MONDAY: Mostly cloudy with isolated flurries, light wind from the south, alpine high temperatures around -6 C.TUESDAY: Mix of sun and cloud, light wind from the northwest, alpine high temperatures around -9 C.
Avalanche Summary
Natural avalanche activity is tapering off after a week of stormy weather. The most recent natural avalanche cycle occurred on Thursday into Friday. In the Monashees, the cycle involved mostly large storm slabs (size 2), while in the Selkirks there were some larger storm slabs (up to size 3) as well as a large few persistent slab avalanches. Over the past week there have been several notable large persistent slab avalanche that have been remotely triggered from skiers on adjacent slopes, particularly in the Selkirks and the northern tip of the Monashees near Valemount. The most recent occurred in the Selkirks on Friday, where a size 2.5 slab was remotely triggered on a south slope at 2200 m from low angle trees. The avalanche failed on a 120 cm deep surface hoar layer.
Snowpack Summary
Strong wind from the southwest has formed fresh wind slabs in the alpine and around treeline, while recent storm snow continues to settle into a slab.A week of stormy weather has deposited 80-120 cm of snow above a weak layer of facets (sugary snow), surface hoar (feathery crystals), and a sun crust (on south aspects) that formed during the dry spell in early December. This layer has been responsible for large persistent slab avalanches over the past week, particularly on north and east facing slopes above 1900 m. The potential exists for smaller avalanches to step down and trigger this deeper layer, resulting in very large avalanches.Another weak layer from mid-November is now buried up to 150 cm, but has been less active recently. At the base of the snowpack is a crust that formed in late October. Concern for this layer is dwindling but it may still be worth considering in places such as steep, rocky, alpine terrain, especially where the snowpack is shallow.
shorton,
Avalanche Canada
