Moderate to strong southwest wind overnight will form wind slabs in lee terrain features at treeline and in the alpine. Fresh wind slabs will be sensitive to human triggers especially when exposed to the sun.
Moderate to strong southwest wind overnight combined with new snow will continue to form wind slabs throughout the night. These fresh wind slabs will be sensitive to human triggers. Be especially cautious when wind loaded slopes are exposed to the sun.
Friday Night: Snow, accumulation 10-20 cm, moderate to strong southwest wind, alpine high -4 C, freezing level 900 m.
Saturday: Mostly sunny, light to moderate northeast wind, alpine high -10 C, freezing level 1000 m.
Sunday: Mostly sunny, light to moderate northwest wind, alpine high -6 C, freezing level 900 m.
Monday: Mostly sunny, light to moderate northwest wind, alpine high -3 C, freezing level 1500 m.
On Thursday a few small (size 1) slab and loose dry avalanches were reported.
On Wednesday several small (size 1) slab avalanches were triggered by explosives and skiers. Several small (size 1) and one large (size 2) loose dry avalanche were reported in the north of the region.
On Tuesday a few small wind slab avalanches (size 1) were observed in isolated lee terrain features.
There was also a report of two size 3-3.5 naturally triggered deep persistent avalanches on a northwest aspect at 2600m. These would have run during or just after the storm on the weekend.
The new snow will be heavily wind affected in the alpine and at treeline after tonight's storm. The fresh snow sits on variable surfaces: Extreme southwest wind leading into last weekend has scoured windward aspects, formed loaded pockets up to 150 cm deep in alpine lees and contributed to rapid cornice growth. Below 1900 m, recent snow overlies a thick crust.
Weak faceted grains and crusts near the base of the snowpack have not been an active avalanche problem recently, despite significant new snow loads. They are still on our radar, especially in inland parts of the region.
