Confidence
Fair - Freezing levels are uncertain on Thursday
Weather Forecast
Wednesday: Possible sunny breaks with isolated flurries, winds moderate from the west and alpine temperatures -8. Freezing level rising to 1000m.Thursday: Light snow, winds moderate from the west and alpine temperatures of -6. Freezing level rising to 1300m.Friday: Light snow throughout the day, light southwesterly winds and alpine temperatures -5. Freezing level rising to 1800.
Avalanche Summary
Numerous loose dry avalanches (size 1.5) failed naturally (some with cornice fall as the trigger) and with skier traffic in steep terrain on Friday and Saturday. In the south-east of the region, a couple of size 2 slabs were triggered by explosives.
Snowpack Summary
10-30 cm of snow which fell on Friday added to recent snowfall above old surfaces including loose dry snow, old wind slabs and sun crusts. This recent snow has been shifted onto lee slopes by strong SW to NW winds. New storm slabs, cornices and wind slabs are likely. Mid and lower snowpack layers are generally well settled and stable.
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.