The avalanche hazard has increased slightly with winds creating new wind slabs and sluffing in steep alpine terrain features. Some weaknesses persist in the mid and lower snowpack and while reactivity of the lower layers has been limited, avalanches are still possible. Keep this in mind if entering steep committing terrain.
Increasing winds are moving the 10-25 cm of low-density storm snow around and forming new wind slabs in lee alpine areas. This new snow sits on the Feb 3 crust, and any slab or sluff will likely travel far and fast in steep terrain features.
Two persistent layers from mid-January and the end of December exist in the mid-pack down roughly 30 and 50 cm. There has been minimal natural activity and infrequent triggering of these layers recently but the weakness is still present and should be considered in more committing terrain.
Some natural sluffing up to size 1 in steep alpine terrain was observed on Saturday and a few small wind slabs up to size 1.5. One size 3 natural was observed in the Egypt Lake area in extreme terrain that was likely triggered by wind loading and stepped down to the deeper layers.
Ski cutting and explosive work produced new wind slab avalanches up to size 2 at local ski areas. Explosive work at Sunshine on Friday triggered one size 2 on the persistent mid-pack facets.
Small wind slabs forming in lee areas of the alpine with increased West winds and some sluffing in steep terrain. 10-25 cm of recent storm snow sits over the Feb 3 crust that is present on all aspects except north above 2500 m. This crust ranges from 1-15 cm thick, with the thickest found in Yoho. Mid-pack weak layers from Jan and Dec are down roughly 30 and 50 cm respectively. Facets and depth hoar make up the basal layers of the snowpack in most locations.
Another Pacific System will track across the Rockies on Sunday. 2 to 4 cm of snow is anticipated. Ridgetop winds will generally be from the west and moderate to strong overnight, easing to light to moderate during the day and picking up again in the evening. Treeline temperatures will range from -5 to -10°C.
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