The sun can pack a punch this time of year. Be aware of signs of deteriorating stability such as snow pin-wheeling down slopes or small point-release avalanching below cliffs.
Weather Forecast
WEDNESDAY: Mix of sun and cloud / Light to moderate southwesterly ridgetop winds / Alpine high of -5 with an above freezing layer of air between 1300-1700 m in some areas of the region.THURSDAY: Cloudy with flurries / Light to moderate southwesterly ridgetop winds / Alpine high of -5 FRIDAY: Mostly cloudy with sunny breaks / Light westerly ridgetop winds / Freezing level rising to around 1600m.
Avalanche Summary
Numerous natural and explosive triggered storm slab avalanches up to size 2.5 were reported on all aspects and elevations in this region over the weekend. On Monday an explosive triggered size 2 wind slab was reported on a northeast aspect near Fernie. Currently, slab avalanches are most likely to be human triggered in wind effected areas.
Snowpack Summary
Last week's storms totaled 100cm of snow accumulation in parts of the region. This storm snow overlies various old surfaces including old hard wind slabs, crusts, facets and more isolated surface hoar. In the upper to mid snowpack, a surface hoar layer buried mid-February is now 80 to 100 cm below the surface on sheltered northerly aspects. Deeper in the snowpack, the widespread mid-December weak layer sits about 200 cm deep. This consists of a crust, facets or surface hoar. Near the base of the snowpack, a crust/facet layer could be awoken from a thin-spot trigger point, or with a very large load like a cornice fall.
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.