Avalanche Forecast
Issued: Feb 18th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
David McCashin,
Parks Canada
Human triggering is possible in terrain where wind slab is present. This will likely trigger the deep instability. At this time of year, solar input on some aspects begins to become a factor.
Summary
Weather Forecast
Clear skies, light alpine winds and cold valley temperatures overnight will set up a temperature inversion. Wednesday will be clear with cloudy periods with light ridge winds, precipitation nil, alpine temperature -14C
Find the Alberta Rockies weather synopsis here: Mountain Weather Forecast
Snowpack Summary
Variable strength windslab on the surface. Pronounced cornice development on northerly aspects and cross loaded features treeline and above. The mid-pack is bridging the deeper basal facets and depth hoar in some locations.
Average HS at treeline: ~180cm.
Avalanche Summary
Experienced back-country users remotely triggered a very large avalanche (sz 4) on Whistlers Peak on Sunday. The pair observed significant wind effect in the area and unknowingly triggered the windslab from 100m away, which then initiated the entire season's snowpack on the deep persistent layer. Further details here: MIN
Confidence
Problems
Wind Slabs
Wind slabs are widespread through the region with new and previous loading in lee features. Sensitivity will vary with local loading and wind patterns.
- Watch for pockets of hard windslab in steep alpine terrain features..
- Assess start zones carefully and use safe travel techniques.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Shallow snowpack areas, windslabs and/or large triggers such as cornice failures could trigger this deep layer. The consequences of triggering will likely be severe!
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 19th, 2020 4:00PM
