Avalanche danger may spike on slopes receiving direct sun. Avoid travelling on or underneath sun-baked terrain.
Confidence
Fair - Due to variable snowpack conditions
Weather Forecast
Sunday-Tuesday: A mix of sun and cloud with light winds. A few flurries are possible on Tuesday. Alpine temperatures near -2, dropping during overnight periods.
Avalanche Summary
Very little activity was reported on Friday. On Thursday, wind slabs were triggered naturally and by skiers in the size 1.5-2 range. Skiers also triggered small storm slabs which failed on a buried crust. On Wednesday, a widespread natural cycle was observed, with avalanches to size 2.5 failing with solar warming. Cornice fall was also occurring.
Snowpack Summary
The snowpack is variable across the region. Recent storm snow has been redistributed by shifting winds into wind slabs over various crust layers in the upper snowpack. On sun-baked slopes, a melt-freeze cycle is in play at the snow surface, leaving a crust behind during overnight cooling, which breaks down by day. Surface hoar, buried down about 50-70 cm, still shows reactivity in snowpack tests, but in general, triggering this layer has become less likely. It still remains possible with a heavy load or from a thin-spot trigger point. Cornices are large and unstable in some areas. Warm temperatures may weaken them further.
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.