South Rockies

Wind continues to blow recent new snow into windslabs along exposed treeline & in the alpine. Avoid steep or convex features that have wind deposited snow - especially when overhead cornices loom. Large destructive avalanches remain possible. Enjoy the holidays and play safely!

A weak weather system overnight Friday into Saturday from the south will bring mainly cloudy skies, continued moderate strong west winds and light precipitation ahead of a building high pressure.

Friday night: Mainly cloudy with isolated flurries trace to 3cm new snow. Alpine low temperatures near -6C and freezing levels dropping to valley bottom with mild temperature inversion. Ridgetop wind moderate gusting strong from the southwest.

Saturday: Mix of sun and cloud with a trace of new snow. Alpine high temperatures near -3C and freezing levels valley bottom. Ridgetop wind moderate gusting strong from the west.

Sunday: Mix of sun and cloud. Alpine high temperatures near -6C and freezing levels valley bottom. Ridgetop wind light gusting moderate to strong from the west/northwest.

Monday: Mix of sun and cloud. Alpine high temperatures near -7C and freezing levels valley bottom. Ridgtop winds light and variable.

No new reports on Friday at the time of publishing, however the snowpack is still recovering from the recent storm which triggered a widespread avalanche cycle mid-week up to size 3. Natural avalanche activity may taper off a bit but the snowpack remains primed for human triggering, especially in periods of active wind-transport.

On Thursday there were reports of small (size 1) and large (size 2) windslabs from explosive control within the region and explosive controlled very large (size 3) avalanches and cornice triggered very large (size 2.5-3) avalanches from adjacent regions.  

Numerous natural wind slab avalanches up to size 2 were reported Wednesday from our field team in the Crowsnest. These were mostly seen from West aspects in the alpine. 

On Tuesday widespread natural avalanche activity up to size 3 was reported through the region. Many of these avalanches ran deep into their runout zones.

Please consider sharing your observations on the Mountain Information Network. Thank you to those that have already submitted this winter!

30-50 cm of recent storm snow blanketed the region by Tuesday morning. Recent strong to extreme winds have redistributed some of this new snow building touchy wind slabs on leeward slopes. Much of this wind was west / southwest but variable winds have been reported across the region - including northerly winds.A persistent slab 70-100 cm thick now sits on the early December crust. This persistent weak layer, with facetted crystals and surface hoar crystals above and/or below it may be reaching a tipping point. Smaller avalanches may step-down to this weak layer. 

The base of the snowpack consists of a hard melt-freeze crust from early-November that may also have weak crystals around it. This potential avalanche problem is dormant at this time, however; it remains on our radar. The most likely spot to trigger it would be on thin and rocky slopes or, like above, from step down avalanches in the recent storm snow.

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Shooting cracks, whumphs and recent avalanches are strong indicators of an unstable snowpack.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
• Avoid exposure to slopes that have cornices overhead.
• Uncertainty is best managed through conservative terrain choices at this time.