Give cornices a respectful berth.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
THURSDAY: Cloudy. Around 10-15 cm snow. Treeline temperature near -4. Moderate southerly winds.FRIDAY: Mix of sun and cloud. Treeline temperature near -3. Light winds.SATURDAY: Mainly sunny. Treeline temperature near -1. Light winds.
Avalanche Summary
A natural cycle of size 1-2 loose snow avalanches was reported on Tuesday and Monday. A chunk of falling glacial ice triggered a size 3.5 slab on a north-west aspect. On Sunday, a skier triggered a size 1.5 persistent slab avalanche on a southwest aspect at 2100m. On Saturday a skier triggered a size 1.5 persistent slab avalanche on a northeast aspect at 1500m with a 1 m crown. Both were in the south of the region.
Snowpack Summary
Solar aspects have developed new sun crusts, which new snow may sluff easily on. Recent storm snow continues to settle. A couple of layers buried in mid-late February (down around 50-100 cm) are variably reactive, but both have the potential to create surprisingly large avalanches if triggered. Initially, these interfaces were most reactive on solar aspects, where they present as buried sun crusts. However, persistent slabs have been triggered on shady aspects too, where surface hoar and/or facets exist.Deeper persistent weak layers from January and December are generally considered dormant, but could wake up with forecast warming, 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 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.
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.