Recent snowfall may continue to be reactive to riders on Sunday. Use added caution at higher elevations where the wind has formed touchy deposits. Also use caution in openings below treeline such as cutblocks, where a buried weak layer may be touchy.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
SATURDAY NIGHT: Cloudy with snowfall, accumulation 1 to 5 cm, light to moderate north wind, alpine temperature -22 C.SUNDAY: Mostly cloudy with isolated snowfall, accumulation 1 to 3 cm, light to moderate northeast wind, alpine temperature -24 C.MONDAY: Mostly clear skies, light northwest wind, alpine temperature -16 C.TUESDAY: Mix of sun and cloud, light west wind, alpine temperature -14 C.
Avalanche Summary
Several wind slabs were triggered by skiers and explosives on Friday and Saturday. They were large (size 2), 20 to 40 cm deep, and in alpine terrain.
Snowpack Summary
Around 20 cm of snow fell Friday and Saturday, with a bit more expected on Sunday. The snow likely has slab properties where it fell with wind at higher elevations and could be loose in sheltered areas.The mid-January layer of surface hoar is buried around 50 to 80 cm. The surface hoar is found on shaded and sheltered slopes and is most prominent between 1600 m and 1900 m but has been found up to 2200 m.The middle of the snowpack is generally consolidated. The bottom half of the snowpack is unconsolidated and composed of weak and sugary faceted grains.
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.