Recent snowfall may continue to be reactive to riders. Use added caution at higher elevations where the wind has formed touchy deposits. Also use caution in any opening below treeline, where a buried weak layer may be touchy.
Weather Forecast
SUNDAY NIGHT: Partly cloudy, light to moderate northeast wind, alpine temperature -22 C.MONDAY: Clear skies, light north wind, alpine temperature -20 C.TUESDAY: Increasing cloud with afternoon light snowfall, trace accumulation, light to moderate west wind, alpine temperature -14 C.WEDNESDAY: Cloudy with light snowfall, accumulation 1 to 5 cm, light to moderate northeast wind, alpine temperature -13 C.
Avalanche Summary
There was evidence of many small to large (size 1 to 2) wind slab avalanches in the region on Sunday. There was also evidence of 40 cm slabs scrubbing to ground in very shallow snowpack areas.
Snowpack Summary
Around 20 to 30 cm of snow fell within the past three days, with the highest amounts in the south of the region. 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. Snowpack test results suggest that this layer could produce large avalanches.The middle of the snowpack is generally consolidated. The bottom half of the snowpack is unconsolidated and composed of weak and sugary faceted grains. There is potential for shallower avalanches to step down to these deeper weak layers.
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.