Wind slabs exist on all aspects at higher elevations, so the best and safest riding is in sheltered terrain.
Confidence
Moderate - Intensity of incoming weather systems is uncertain
Weather Forecast
THURSDAY: Cloudy, 30-50 km/h east winds, alpine temperatures at -10.FRIDAY: 5-15 cm of new snow, 20-30 km/h southwest winds, alpine temperatures at -10.SATURDAY: 5-15 cm of new snow, light southwest winds, alpine temperatures at -8.
Avalanche Summary
On Tuesday, avalanche reports were limited to size 1 wind slabs, including one triggered by a natural cornice fall on a northeast alpine aspect. Explosive cornice control broke off large chunks of cornice, but did not trigger any avalanches on the slopes below. Wind slabs may remain reactive to human-triggering throughout the week in alpine and treeline terrain.
Snowpack Summary
Surface conditions are highly variable throughout the region. Last weekend strong southerly winds scoured windward features and formed hard and stubborn wind slabs on lee features. However, northeast winds are currently loading south and west aspects, resulting in a complex distribution of wind slabs in exposed terrain. Low density snow remains in sheltered areas and offers the best riding. Surface snow has begun to facet with the cold air temperatures, and will likely create a weak interface when the next storm arrives. The mid-pack is generally strong, with a widespread mid-November crust buried 70-100 cm at treeline and anywhere from 30-200 cm in alpine terrain. Recent snowpack and explosive tests have shown the crust to be unreactive, but it could remain a problem in shallow alpine start zones.
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.