More flurries and gusty winds continue to build and develop slabs. A cautious approach is recommended during this active weather period.
More snow and wind will continue to develop slab properties and redistribute loose snow. The deepest and most reactive deposits will be in the alpine and around ridges and lee features at treeline.
Wednesday Night: Scattered flurries, 5-10 cm. Alpine temperature -5 C. South wind 25-45 km/hr. Freezing level 600 m.
Thursday: Flurries, 10-20 cm. Alpine temperature -4 C. South wind 20-30 gusting to 50 km/hr. Freezing level 800 m.
Friday: Snow, 10-25 cm. Alpine temperature -6 C. South wind 30 gusting to 60 km/hr. Freezing level 800 m.
Saturday: Flurries, 5-10 cm. Alpine temperature -5 C. Southwest wind 30-45 km/hr.
Early explosives work on Wednesday triggered several storm slab avalanches to size 2, average crown depths were around 30 cm.
A natural avalanche cycle to size 2.5 occurred Tuesday, in steep and leeward terrain at treeline and above. In many cases avalanches failed with input from strong to extreme south and westerly winds gusting upwards of 70 km/hr.
Heavy snowfall blanketed 30-60 cm snow around the region. Winds arewith deeper deposits around leeward terrain features.
The new snow likely covered a weak layer of surface hoar and/or a crust on south-southwest aspects, and is the failure plane for Tuesday's natural avalanche cycle. (Check out this MIN from Sunday before the snow started.)
Now down 40-90 cm, a second surface hoar layer is found under the recent storm snow and a 10-30 cm layer of older snow. Reports suggest this layer can be found on all aspects up to treeline elevations, particularly in areas sheltered from the wind. In the alpine, the recent snow covered hard wind slabs and/or sun crusts on south-facing terrain.
The lower snowpack is generally considered strong, as there has been very little to report in terms of recent avalanche activity or snowpack test results on deeper layers. Snowpack depths at treeline range from 100-200 cm and taper quickly at lower elevations.
