Avalanche Forecast
Issued: Nov 27th, 2020 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
matt,
Avalanche Canada
Its been ridiculously windy the past 24 hours. Our snowpack has dramatically changed and will require us to start from scratch and re-learn its character. Don't casually approach terrain as if it was still last week's snowpack.
Summary
Confidence
Weather Forecast
The upper alpine winds will fade overnight tonight and settle to a relative calm of 50km/hr out of the west. At treeline they should be around 10-20 km/hr and also westerly. A flurry or two will give a centimeter or two of snow. And temperatures will steadily fall to -7 by mid afternoon.
Avalanche Summary
Several wind induced loose dry avalanches from alpine gullies. We also witnessed a healthy sz2 near Mt Storelk. It likely started with a cornice fall and triggered slope as it travelled.
Snowpack Summary
The last 24 hours have been extremely windy, even for us. Highwood pass had a few small patches of preserved snow, but for the most part, our snow has blown to Saskatchewan. Widespread wind affect is an understatement. That means our two weak layers will be at different depths than what we've known so far. Take some time to dig and re-familiarize yourself with the layers and their reactivity. The crust may be much deeper than we expect and surface windslabs will be widespread and stiffer than usual. Expect them to become more "triggerable".
Terrain and Travel
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Avoid steep convex slopes.
- Pay attention to isolated alpine features as well as cross-loaded features at treeline.
Problems
Wind Slabs
Extreme winds and warmer temps often create slabs in places we wouldn't expect. Alpine faces will have pockets of new wind slabs created from spindrift rolling down/across faces. Avoid being below cliffs. Treeline rolls will also be freshly loaded.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Exposed, west facing alpine slopes have been stripped bare. This means the Nov 5 layer will be buried deeper than expected in some areas. In turn, this means that deeper layer will be more stressed with the additional load.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 28th, 2020 3:00PM
