Strong southwest wind will redistribute the new snow and form wind slabs in lee terrain features at all elevations. Snowfall amounts are uncertain. The avalanche danger will increase throughout the day with increasing snowfall amounts and continuing wind.
Strong wind from the southwest will load lee terrain features with the new snow at all elevations. The size of wind slabs and sensitivity to triggering will increase throughout the day with increasing snowfall amounts and continuing wind.
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.
On Sunday there were reports of explosives controlled wind slab and storm slab avalanches to size 2 in the alpine. There was also a report of two size 3-3.5 naturally triggered deep persistent avalanches on a northwest aspects at 2600m. These would have run during or just after the storm on the weekend.
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. Light to moderate amounts of new snow are beginning to obscure this lingering wind effect. Below 1900 m, recent snow overlies a thick crust and tapers quickly with elevation.
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.
Thursday Night: Mix of clouds and clear skies with isolated flurries, moderate northwest wind, alpine high -5 C, freezing level 1000 m.
Friday: Snow, accumulation 15-20 cm, strong southwest wind, alpine high -3 C, freezing level 1000 m.
Saturday: Mix of sun and cloud, accumulation 5-15 cm, moderate north wind, alpine high -6 C, freezing level 1100 m.
Sunday: Mostly clear, moderate northerly wind, alpine high -5 C, freezing level 900 m.
