Variable wind direction continues to develop pockets of new windslab in the alpine.
Weather Forecast
Mix of sun and cloud overnight with freezing levels dropping down to valley bottoms. Mix of sun and cloud with moderate – strong southwest winds and freezing levels rising up to 2100 metres on Monday. Mix of sun and cloud on Tuesday with light winds and freezing levels around 2100 metres. Cloudy with snow on Wednesday.
Avalanche Summary
A Windslab has been reported size 2.0 that was about 20 cm deep and ran 300 metres. Explosives control released a couple of 50 cm deep pockets in the alpine size 2.5
Snowpack Summary
Roughly 5-10 cm of recent storm snow adds to the variable amounts of dry facetted snow on top of the mid-February crust with associated buried surface hoar in sheltered areas, or, more recent melt-freeze crusts on sun-exposed slopes. The late-Jan crust/surface hoar layer can be found about a metre below the surface in deeper snowpack areas. The mid-January surface hoar, can be found below that. These layers have gained significant strength, and chances of triggering these weaknesses have decreased dramatically. However, triggering may be possible with a large input such as cornice fall, or an avalanche stepping down, especially on slopes that see a lot of sun.
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.