Caution if the sun comes out - avoid steep sunny slopes where the snow will lose cohesion.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
THURSDAY: Mix of sun and cloud. Freezing level at valley floor. Light to moderate winds.FRIDAY: Mix of sun and cloud. Freezing level at valley floor. Light to moderate winds.SATURDAY: Mix of sun and cloud. Freezing level at valley floor. Light to moderate winds.
Avalanche Summary
Its been fairly quiet the last couple of days, with only reports of explosives triggering small storm slabs.
Snowpack Summary
You are likely to find variable surfaces in open terrain after recent strong winds took out their fury on the upper snowpack. Fragile cornices and hard and soft wind slabs can be found on many alpine and treeline slopes. Ongoing cold temperatures are helping to break down and soften these.A crust/surface hoar interface is about 40-60 cm down, but is spotty in distribution. In sheltered areas where the surface hoar exists, it is reactive in snowpack tests. Deeper in the snowpack, the widespread mid-December weak layer sits about 120-160 cm deep. This consists of a crust, facets or surface hoar. Near the base of the snowpack, a crust/facet layer could be awoken from a thin-spot trigger point, or with a very large load.
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.