Evidence of a wind slab cycle was evident on Sunday. Human triggering remains likely. The Mt Whymper and Simpson avalanche closure zones are CLOSED on Mon Jan 10 for avalanche control.
Strong SW wind has been loading lee areas in the alpine and tree line. This, coupled with a slight rise in temperature will increase the likelihood of human triggering.
The Dec. 2 crust/facets are down 60-100 cm throughout the region. Sparse and sporadic activity has occurred mainly in Kootenay (as recently as Jan 8). A high degree of uncertainty remains around this layer.
Wx models suggest there is little respite in the wind, which will generally remain in the strong range from the W/SW for the next few days. Temperatures will be slightly warmer than seasonal but the freezing level should remain below surface. A small to moderate amount of new snow (10-20cm) is expected late on Tuesday.
Strong wind from the SW is redistributing available snow into lee areas in both the alpine and treeline. These slabs may bond poorly to the underlying facets from the cold snap. The Dec 2 crust/facet interface is down 60-100 cm, and the snowpack is very faceted in shallower areas.
Two size 2 wind slab avalanches were observed in the Bow Summit area on Sunday. Also, Massey's near Field, went size 2.5 and poured over the ice climb in the past 24 hours. Lake Louise patrollers triggered a size 2 wind slab with explosives. Please see yesterdays MIN report of the avalanche that occurred on the Dec 2 crust in the Simpson paths.
