Wind slabs that formed over the weekend are expected to remain reactive to human triggering. Use a conservative approach to terrain selection and continually assess conditions while you travel.
Weather Forecast
An Arctic front pushes southward on Monday bringing cold, dry conditions for the next few days. A mix of sun and cloud is expected on Monday with light to moderate alpine winds from the northwest and treeline temperatures around -15C. Conditions are expected to remain similar on Tuesday and Wednesday with sunny conditions, light northerly winds in the alpine, and treeline temperatures dropping to around -20C.
Avalanche Summary
On Sunday, explosives and ski cutting in the north of the region produced wind slab avalanches up to size 2. These wind slabs were on northerly aspects and were typically 10-20cm thick but one was reported to be up to 40cm thick. On Monday, the wind slabs that formed over the weekend are expect to remain reactive to human-triggering. These wind slabs are expected to be most reactive on north through east aspects in the alpine.
Snowpack Summary
Snowpack observations are still very limited in this region. The new snowfall and strong alpine wind on Friday and Saturday formed wind slabs up to 40cm thick in the north of the region. The mid-November crust is typically down 50-90cm. Weak facets are reported to be forming above and below this crust layer in the north of the region. With the upcoming cold weather, continued faceting is expected around this layer and it has the potential to create a persistent slab problem in the future as more snow accumulates.
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.