New snow and strong winds have formed reactive storm slabs in the alpine and treeline, these may trigger the deeper weak layers creating large destructive avalanches.
Human triggering of persistent slab avalanches at lower elevations remains possible.
A surface hoar layer, down 60-80cm, is reactive to human triggering. A second layer of large surface hoar is buried 80-100cm deep and sits on a crust. Use caution in terrain that has not seen recent rider traffic where triggering is most likely.
See Avalanche Canada's blog post for addition info.
25cm of new snow with strong winds has formed a new storm slab. Approach open slopes and lee features with caution. With 2 weak layers in the upper snow pack storm slabs in motion could step down and also trigger the persistent slab problem resulting in very large avalanches.
New snow and wind on Monday triggered a natural avalanche cycle up to size 3 in the hwy corridor and a field team easily ski cut several storm slabs size 1-2. Recently human triggered wind slab and persistent slab avalanches have been reported throughout the region on the MIN.
Over the past week numerous size 1 to 2 persistent slabs were triggered from low angle terrain at tree-line and below. These have been failing on surface hoar layers in the upper snowpack.
Up to 30 cm of new snow fell on old surfaces of settled snow and wind affect and was redistributed by strong SW winds on Monday.
The Feb 9 surface hoar (SH) is down 60-90cm and remains reactive in snowpack tests, it sits on a crust on solar slopes.
The Jan 26th layer, composed of surface hoar/facets/crust, is buried 80-100cm deep. The largest surface hoar is preserved in sheltered areas below treeline.
A brief lull on Tuesday before the next storm arrives, maybe as much as 50cm by the weekend.
Tonight: Flurries, trace of new snow. Alp low -11°C. Moderate SW winds. Freezing level (FZL) 500m.
Tues Sunny, no precip. High -10°C. Light gusting to moderate SW winds. FZL 800m.
Wed Snow 16cm. High -8°C. Extreme SW winds. FZL 800m.
Thurs Snow 18cm. High -7°C. Extreme SW winds. FZL 1000m.
