Avalanche Forecast
Issued: Jan 11th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs, Wind Slabs and Deep Persistent Slabs.
mark herbison,
Parks Canada
Problems within the snowpack are complex and will likely persist for some time. There is great skiing, but now is the time for conservative decision making.
Summary
Weather Forecast
Mainly cloudy with isolated flurries of low density, fluffy snow. The temps will begin to drop and will range from -12 to -26, as the winds will shift Sunday morning and be light from the East. It will remain cold and mainly sunny until at least late next week.
Snowpack Summary
30-50 cm of snow since Jan 1 sits over a variety of surfaces including facets, surface hoar and sun crust. Stability tests throughout the region show 'sudden' results on this interface. Reactive wind slabs exist in alpine and some tree line locations. In most areas there is a well settled mid-pack over top of a weaker basal layer.
Avalanche Summary
Parks Canada responded to a size 2.5 skier triggered avalanche on the South flanks of Mt. Hector yesterday. Its suspected that the initially triggered wind slab stepped down to deeper layers.
Several naturals sz 2-3 were observed Thursday throughout the forecast region, some of which failed at the ground within the deep persistent layer.
Confidence
Problems
Persistent Slabs
This layer consists of surface hoar / facets / sun crust and is down 40-60 cm throughout the region and is producing 'sudden' results in stability tests. Several skier triggered avalanches have occurred recently on this layer.
- If triggered the persistent slab may step down to deeper layers resulting in large avalanches.
- Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Wind Slabs
Recent storm snow and mod to strong winds have created wind slabs in alpine and treeline elevations. It will take several days for these instabilities to settle out.
- If triggered the wind slab may step down to deeper layers resulting in large avalanches.
- Use caution in lee areas. Recent wind loading have created storm slabs.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The potential for deeper releases on the basal layers still exist. Several large avalanches have occurred on this layer in past few days. Click on Forecast Details tab for more information.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
- Avoid shallow snowpack areas where triggering is more likely.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 12th, 2020 4:00PM
