Avalanche Forecast
Issued: Feb 26th, 2021 5:01PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Loose Dry.
Conrad Janzen,
We have some uncertainty as to how well the recent storm snow is bonding to the previous facets in some areas. Do some investigation before committing to steeper or larger terrain features. New snow sluffing in steep terrain is also a concern.
Summary
Weather Forecast
Alpine winds will start off light on Saturday and start rising later in the afternoon into the moderate range as they shift to the NW. Temperatures will remain cool with treeline values between -10 to -15 Celsius. A few flurries are expected but no significant accumulations, and there may be some sunny breaks in the afternoon.
Snowpack Summary
Up to 15 cm of new snow on Friday. Recent snow and wind have created wind slabs in alpine lee areas and exposed treeline slopes. In thin snowpack areas the recent 30-50 cm of storm snow sits over weaker facet interfaces which fail more easily in tests. In deeper snowpack areas there was less facetting, and the recent storm snow is bonding better.
Avalanche Summary
Ski hills reported some small wind slabs up to size 1.5 in lee areas of the alpine with ski cutting and explosives. Investigation of a recent skier triggered size 2 avalanche on Wolverine Ridge by Lake Louise, in an area with a total snowpack of 80 cm, showed a failure on weak facets below the recent snow that then stepped down to the basal facets.
Confidence
Intensity of incoming weather systems is uncertain on Sunday
Problems
Wind Slabs
Ongoing new snow and wind continue to create wind slabs in alpine and exposed treeline lee areas. These have been becoming more difficult to trigger, but places where the new wind slab sits over a weaker facet interface are still a concern.
- Use caution in lee areas. Recent wind loading has created slabs over weaker snow.
- Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
Areas that got more snow in the past two days are seeing significant sluffing in steep terrain. In most places this can be managed with good ski cutting and sluff management techniques, but it could be a problem in confined gullies or couloirs.
- On steep slopes, pull over periodically or cut into a new line to manage sluffing.
- Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 27th, 2021 4:00PM
