The new snowfall has created touchy new windslabs in specific areas, particularly transitioning from treeline into the alpine.
Weather Forecast
Snowfall amounts tapering off steadily, with only light scattered flurries expected through to the weekend. Temperatures will continue to cool, dipping down to -15C in the alpine. Winds decreasing and returning to the light range, gusting moderate from the Southwest.
Snowpack Summary
5-10cm of new snow has been pushed around by recent moderate SW winds, forming new windslabs in the alpine. This new snow covers a couple interesting surface hoar layers in the top portion of the snowpack - Jan 7 (5-10mm well preserved) and Jan 17 (2-5mm). These layers may present a touchy interface for new windslabs and storm snow.
Avalanche Summary
Limited visibility, but field teams report several natural slab avalanches to sz 2, originating in the alpine and running to the bottom of the track. The Jan 7 surface hoar layer was reactive to skier traffic, and ski cutting produced numerous sz 1 wind slabs in the Hilda Creek area. More activity is expected on the Jan 7 layer over the next while.
Confidence
Due to the number of field observations
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.