Avalanche Forecast
Issued: Dec 23rd, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
Adam Greenberg,
Parks Canada
This is a dangerous time. We are through the storm and natural activity has tapered off, but the potential for large avalanches running to the valley bottom remains. Remember: Considerable means human triggering of avalanches is likely.
Summary
Weather Forecast
Tuesday: Freezing levels dropping to valley bottom. Flurries throughout the day and Moderate SW winds.
Wednesday: Light winds and a mix of sun and cloud for christmas. Alpine high -9
Thursday: Cloudy with west winds increasing through the day and a mild inversion forming.
Snowpack Summary
There is a highly variable snowpack across the forecast region. Generally the snowpack is wet and thin below 1800m. Above that elevation, the Cameron Lake area received the most snow in the storm with 85-100cm since Thursday. This sits on a weak facet/crust combo that is now down 150cm. The front ranges hold a thinner more wind affected snowpack.
Avalanche Summary
A widespread natural cycle occurred this past weekend, with avalanches to size 2 in the storm snow and some larger ones failing on deep persistent weak layers. A size 3 natural avalanche occurred on Mt Bertha early Sunday morning covering the Bertha Falls trail in debris, and a similar avalanche was seen on Mt. Crandell.
Confidence
Problems
Wind Slabs
Wind slabs will be thicker and more reactive the higher you go. Snow amounts change dramatically above 1800m.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Use caution in lee areas in the alpine and treeline. Recent storm snow has formed wind slabs.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
As natural activity on this layer begins to slow down, it is tempting to believe the problem has passed. This layer could still be triggered in thin areas, or by large triggers including cornices or smaller avalanches.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
- Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 26th, 2019 4:00PM
