Strong winds and some new snow will be driving the avalanche danger at higher elevations. Use terrain features to your advantage while avoiding wind loaded pockets, and unsupported roll-overs.
Confidence
Low - Intensity of incoming weather systems is uncertain on Tuesday
Weather Forecast
We're expecting windy conditions and some snow on Tuesday, followed by unsettled weather, sunny breaks and the chance of convective flurries through Thursday. TUESDAY: Flurries (5-10cm) with some local higher accumulations. Moderate to strong south / west winds 25-65 Km/hr. Freezing level to 1700 metres with alpine high temperatures around -4. WEDNESDAY: Sunny with cloudy breaks. Moderate west winds 30-40 Km/hr. Freezing level 1600 metres with alpine high temperatures around -3.THURSDAY: Cloudy with isolated flurries (2 cm possible). Winds becoming light, west. Freezing level to 1400 metres with alpine high temperatures of -5.
Avalanche Summary
On Sunday we received reports of a skier triggered avalanche on a west aspect near 2200m in the north of the region. Also on Sunday a cornice collapse on a north east aspect near 2500m resulted in size 2 debris, but did not pull out a slab below.On Saturday, skiers were able to cut a size 1.5 wind slab on a north west aspect (crown height 10-15cm) in the east of the region. Looking forward, fresh wind slabs will be reactive to human triggering over the near term.
Snowpack Summary
At tree line and above, most of the region's upper snowpack consists of a wind-affected 10-20 cm layer of snow. This sits on previous layers of storm snow that are separated by temperature and sun crusts at lower elevations and on south aspects. Surface hoar layers have been reported between these old storm snow layers on shaded aspects at higher elevations and can likely now be found at approximately 20 and 40 cm below the surface.New snow amounts taper quickly with elevation and below about 1900 m, reduced accumulations sit on a supportive crust on all aspects. Deeper persistent weak layers from mid-late February (down 40 -100 cm deep) as well as January and December layers are generally considered dormant, but could wake up with a surface avalanche stepping down, cornice fall, or a human trigger in a shallow or variable-depth snowpack area. These layers consist of sun crust, surface hoar and/or facets. Facets also linger at the base of the snowpack.
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.