Northern parts of the region may have similar conditions to the North Columbia and Glacier National Park regions. Check these bulletins to get the complete picture.
Confidence
Fair - Due to variable snowpack conditions
Weather Forecast
Wednesday: Light snow. Moderate SW winds. Freezing level near 1500 m. Thursday: Light snow. Light to moderate SW winds. Freezing level near 1800 m. Friday: Moderate to heavy snow. Light SW winds. Freezing level near 1800 m.
Avalanche Summary
On Sunday, a naturally triggered size 2.5 slab failed on a buried crust. Numerous small loose dry avalanches were also observed. In neighbouring Glacier National Park, skiers triggered a size 3 slab on a buried crust on an east aspect in the alpine on Monday. The slab above this interface may be reaching tipping point with incremental loading from snow and wind.
Snowpack Summary
Up to 40 cm recent storm snow has been shifted into variable wind slabs at treeline and above. In some areas, easterly winds have led to wind slabs on different slopes than you might usually expect. Cornices are very large and potentially destructive.A weak interface down about 60-120 cm consists of a crust on solar aspects, and surface hoar on high-elevation northerly aspects. Recent very large avalanches in neighbouring regions to the north failed on this interface. The slab above this interface may be reaching tipping point with incremental loading from snow and wind. Periods of warming or solar radiation may increase the reactivity of cornices and storm slabs.
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.