A firm slab, sitting over several persistent weak layers, can be found in isolated areas in the forecast region. Triggering it remains possible and would be a high consequence event.
Weather Forecast
Monday will be cloudy with sun and flurries, trace amounts of snow, and -14 with light gusting moderate West winds. Tuesday will be sunny periods and flurries, trace snow, -17 to -12 and light gusting strong West winds. Wednesday will be similar to Tuesday with lighter winds.
Snowpack Summary
Strong W and N winds have left wind slabs and wind effect in open areas. The upper snowpack has settled to form a cohesive stiff slab that is sitting on three persistent weak layers mid-pack (down 50 to 80cm) which can be found throughout the forecast region, and did produce many large avalanches during the Feb 8th cycle.
Avalanche Summary
Helicopter patrol down highway 93 noted no new avalanches and visibility was good. This past week there was minimal natural activity yet it is still prudent to treat slopes that did not avalanche in the Feb 8 cycle as being suspect.
Confidence
The weather pattern is stable
Problems
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.
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.