Avalanche Forecast

Moderate - Forecast snowfall amounts are uncertain

Sunday night: Isolated convective flurries bringing 5-20 cm of new snow. Light variable winds.Monday: Mainly cloudy with lingering isolated flurries and a trace of new snow. Light northeast winds. Alpine high temperatures around -11.Tuesday: A mix of sun and cloud. Light southwest winds. Freezing level to 800 metres with alpine high temperatures around -9.Wednesday: Cloudy with isolated flurries and a trace of new snow, increasing overnight. Freezing level to 1300 metres with alpine high temperatures around -6.

On Saturday a skier triggered a large slab avalanche (size 2.5) on a south aspect at 2600 m. The avalanche failed on a buried sun crust 150-200 cm below the surface. Another large (size 2.5) wind slab released naturally from a steep southeast-facing alpine slope in the St. Mary's area. Explosives control in the northern half of the region produced numerous storm slabs ranging from size 1.5-2.5 at treeline and alpine elevations. Crown fractured ranged from 30-100 cm. All aspects were represented in results, with the majority of activity focused on northeast to northwest aspects in the alpine.Several size 1-2 natural wind slabs and storm slabs were reported on a range of aspects on Thursday and Friday. A few size 1 skier triggered slabs on were reported on south aspects around 2300 m, including one that partially buried a skier.On Wednesday, several skier triggered avalanches up to size 2.5 were reported from all aspects above 2000 m. These avalanches predominantly failed on the late-March interface, with crown depths from 20-50 cm deep and up to 100 cm in some areas.

Light new snow amounts have begun to accumulate over wind-affected surfaces as well as a new crust on solar aspects. Below the surface, accumulations from last week vary from up to 80 cm amounts in areas just east of Kootenay Lake to a mere 20-40 cm in eastern parts of the region. The storm snow sits on an interface buried in late-March that consist of crusts below 1900 m and on south aspects, and surface hoar on shaded aspects at higher elevations. Other slightly deeper surface hoar/facet layers have been reported on shaded aspects at higher elevations and may be found approximately 40-60 cm below the surface.Deeper persistent weak layers from mid-late February as well as January and December layers, are still being monitored by professional observers, but are generally considered dormant. Facets also linger at the base of the snowpack.