Wind slabs at upper elevations are the main concern. Avalanches are unlikely where a thick supportive crust caps the upper snowpack.
Wind has recently switched direction from southwest to northwest. At treeline elevations, wind slabs may overly a crust which may make for a favourable sliding surface.
Monday Night: Mostly cloudy. Light northwest wind. Alpine high -9 C.
Tuesday: Cloudy with isolated flurries. Light northwest wind. Alpine high -8 C.
Wednesday: Flurries, accumulation 5 cm. Moderate to strong west wind. Alpine high -4 C. Freezing level 700 m.
Thursday: Cloudy with isolated flurries. Light to moderate west wind. Alpine high -3 C. Freezing level 800 m.
Small loose dry avalanches running on rain crust were been observed in wind sheltered areas on Sunday. On Friday and Saturday, a widespread storm slab avalanche cycle was observed size 2-2.5 on all aspects above 1600 m.
Reports of deep persistent avalanches had been periodically coming in over the past few weeks, primarily from the western Boundary area but most recently on Saturday near Nelson. These large, deep avalanches are generally triggered by very large loads (cornice falls or vehicles) in shallow, rocky snowpack areas.
Strong southwest wind leading into last weekend has scoured windward aspects and formed loaded pockets in alpine lees. As high as 2000 m, the upper snowpack contains a series of crusts from recent warming and rain events.
A layer of surface hoar is buried 100-150 cm below the surface in sheltered areas around treeline but has not been associated with avalanche activity recently. Weak facet/crust layers near the base of the snowpack are particularly noteworthy in the western Boundary area.
