Expect to find wind slabs in exposed terrain features from recent snowfall with strong winds. Although a cool day is forecasted, assess snowpack warming on southerly aspects from the sun -- it could weaken the snow and trigger avalanches.
Weather Forecast
SATURDAY: Mostly sunny, light southwesterly winds, alpine temperature -13 C, freezing level 700 m.SUNDAY: Increasing clouds with light snowfall, accumulation 2 to 5 cm, light southwesterly winds, alpine temperature -10 C, freezing level 800 m.MONDAY: Cloudy with morning snowfall, accumulation 10 cm, light easterly winds, alpine temperature -15 C, freezing level 700 m.
Avalanche Summary
On Thursday, large wind slab avalanches were noted on south to easterly aspects in alpine and treeline terrain, being triggered naturally and by snowmobiles.On Wednesday, small to large (size 1 to 3) wind slabs were triggered naturally, generally on northerly to easterly aspects, and in alpine terrain.
Snowpack Summary
10 to 20 cm of new snow fell at higher elevations, with associated strong westerly switching to easterly winds. This new snow fell on previous wind slabs that exist on all aspects in exposed terrain. In sheltered locations, expect to find dry snow in shady areas. A melt-freeze crust is found at low elevations, where the precipitation fell as rain.About 50 cm deep, a crust is found up to 2200 metres. At a similar depth, a layer of surface hoar is found on shaded aspects at treeline in parts of the region.The midpack is well-settled and strong. This overlies sugary facets in thin snowpack areas.
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.