Seek out low density new snow that was sheltered from recent winds. An uptick in alpine winds toward the end of the day may begin to build new slabs at high elevations.
Our new snow at higher elevations has seen extensive wind redistribution as a result of strong to extreme southwest winds. Expect to find increasingly deep and potentially reactive wind slabs as you gain elevation into the alpine. This problem is likely most pronounced on the east slope of the region.
Monday night: Clear. Light northwest winds, increasing into the morning.
Tuesday: Mainly sunny with cloud increasing over the day. Light to moderate west winds increasing over the day and overnight, becoming strong at ridgetop. Alpine high temperatures around -13.
Wednesday: A mix of sun and cloud with isolated flurries. Light to moderate west winds, becoming strong at ridgetop. Alpine high temperatures around -7.
Thursday: Mainly cloudy. Light to moderate west winds. Alpine high temperatures around -8.
Reports from Friday showed small (size 1) wind slabs able to be triggered with ski cutting in the Castle area. More intense snowfall and wind throughout Saturday are likely to have spurred a natural avalanche cycle, focused in high elevation, wind-exposed areas.
On Thursday a cornice fall released a size 2 slab avalanche on the slope below on an east aspect at 2150 m.
On January 16th, a natural, size 2 wind slab stepped down to the deep persistent basal facets below a rock band, details here.
While avalanche danger is now low in areas where a new crust has capped the snowpack, potentially reactive wind slabs are likely to exist in the highest elevations as well as the east slope of the region where heavy snowfall combined with strong to extreme southwest winds during the storm.
Variability in surface conditions is likely to be found in the region. In the Elk Valley and further west, an estimated 5-10 cm of snow sits above a solid new melt freeze crust which has capped the snowpack below about 2000 metres.
As a result of precipitation continuing as temperatures fell on Saturday night on the east slope of the range, roughly 20-30 cm of new snow, tapering with elevation, likely sits above a similar crust.
Above 2000 metres, suspected new snow amounts of 20-40 cm have been heavily impacted by strong to extreme southwest winds that affected the entire region. This new snow overlies previously wind affected surfaces.
A well consolidated mid-pack overlies a generally weak basal snowpack. The bottom 10-20 cm of the snowpack consists of facets and deteriorating crusts. While there has been little in the way of avalanche activity on this layer recently, it may be possible for a large load to trigger it in a shallow, rocky start zone.
