Cold dry conditions continue. Watch for signs of instability such as whumpfing, cracking, and recent avalanches.
Confidence
Moderate - Wind speed and direction is uncertain
Weather Forecast
SUNDAY NIGHT: Clear, light northeast wind, alpine temperatures drop to -28 C.SUNDAY: Sunny, light northeast wind, alpine high temperature near -20 C.MONDAY: Sunny, light northeast wind, alpine high temperature near -13 C.TUESDAY: Sunny with cloudy periods, light southeast wind, alpine high temperatures near -10 C.
Avalanche Summary
A few small wind slab avalanches (size 1) were triggered by skiers on Saturday. On Friday, several small slabs were triggered by humans and explosives (10-30 cm thick). Some small natural wind slab avalanches were also observed.
Snowpack Summary
10-20 cm of recent snow with moderate winds has likely formed wind slabs in exposed terrain. Older wind slabs will be buried under the new snow and may be difficult to detect.A weak layer of facets (sugary snow) and surface hoar (feathery crystals) that was buried in mid-January is down approximately 40-80 cm. This layer is most prominent in the Elk Valley between 1600 m and 1900 m, but it has been found up to 2200 m in some areas. This weak layer may exist in combination with a crust on south-facing slopes. Snowpack tests and avalanche reports suggest that this layer remains reactive to human triggers.The bottom half of the snowpack is composed of weak, sugary facets.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.