When the sun comes out, it could have a de-stabilizing effect on the new snow. Be cautious if the sun burn off the high cloud.
Weather Forecast
Friday: Expect mostly sunny skies, with a chance of high, thin cloud. Winds should be light from the north and alpine temperatures should reach -4.Saturday & Sunday: Expect the ridge to settle in. Sunny skies, light northerly winds and alpine temperatures reaching -1 each afternoon.
Avalanche Summary
Natural activity up to size 2.0 has been observed on northeast aspects where the recent storm snow is 25cm or deeper. Be locally aware of how much new snow you are dealing with.
Snowpack Summary
The dribs and drabs of new snow has ended. Around 30-40cm fell on average, with more (up to 65cm) in the Coquihalla area. Consistent southwesterly winds during the storm period has redistributed the new snow into fresh windslabs on lee terrain features in the alpine and at treeline. The newly buried surfaces are old wind slabs (behind ridges, ribs and on lee slopes) and sun crusts on south and west facing slopes. In isolated locations, this interface is small surface hoar. Down a further 20-50 cm sits a persistent interface comprising of crusts, facets and surface hoar crystals. Recently, this layer has been reactive only in sheltered areas at and below treeline where the surface hoar lingers. A partial block RB6 is the only recent test score that we have seen on this interface (Duffey Lake area). There has been one size 2.0 avalanches releasing on this layer as well. The mid pack is generally well settled.
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.