Keep isolated wind slabs in mind in the alpine, and also remember that triggering a persistent slab is not outside the realm of possibility. Steep thin snowpack areas seem particularly suspect.
Although winds have been light recently, small wind-slabs still exist in lee areas. These slabs sit on the Feb 3 crust, and could travel far and fast in steep terrain features.
The persistent weak layers in the mid-pack are down roughly 30 and 50 cm with weak basal facets at the bottom of the snowpack. Sporadic avalanche activity has occurred on these layers and the theme seems to be steep thin snowpack areas in the alpine. Consider this in more committing terrain.
A size 2 and 2.5 skier-triggered deep persistent slab in the Cirque Forepeak area occurred Tuesday showing that the persistent layers can still be triggered in thin snowpack areas.
Lake Louise patrol reported triggering very small and thin wind slabs in high alpine lee areas with ski cuts.
Sunshine Patrol reported triggering soft slabs 5-10cm thick with ski cuts in the alpine.
No avalanches were observed by the field on Mt. Whymper today.
10-25 cm of recent storm snow sits over the Feb 3 crust. Isolated wind slabs are present in alpine lee areas. The Feb 3 crust is present on all aspects except north above 2500 m and ranges from 1-15 cm thick, with the thickest found in Yoho. Mid-pack persistent 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.
The wind will diminish to the light range for the next two days, and calm-ish conditions are expected. A high-pressure system will build into the region on Wednesday. Lingering cloud will be present until Thursday. No precipitation is expected for a few days. Temperatures will be seasonal with -5 in the valley and -20 at the ridge line.
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