Avalanche Forecast
Issued: Jan 3rd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
ahanna,
Avalanche Canada
Recently formed storm slabs will be most reactive in wind affected areas at treeline and above. Be especially cautious as you transition into wind affected terrain.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
Sunday night: Scattered flurries, moderate southwest wind, freezing level 600 m.
Monday: Snow, 5-10 cm, moderate to strong south wind, alpine high temperature near -3, freezing level 1300 m.
Tuesday: Sun and cloud, moderate southwest wind, alpine high temperature near -7, freezing level 1000 m.
Wednesday: Snow, 5-10 cm, moderate southwest wind, alpine high temperature near -3, freezing level 1200 m.
Avalanche Summary
Numerous natural, human and explosive triggered storm slabs size 1-2.5 were reported on Saturday and Sunday. Check out this avalanche triggered remotely by a skier in Kootenay Pass on the weekend.
With new snow slowly but steadily piling up, the chances of a resurgence of persistent slab avalanches will increase. This incremental loading will likely make it difficult to predict when this layer may once again reach a tipping point and start producing avalanches. This problem is best managed with conservative terrain selection.
Snowpack Summary
30-60 cm of recent storm snow has seen significant wind affect at upper elevations. In sheltered areas, the recent snow may sit over surface hoar.
Two weak layers are buried in close proximity to one another. They are 70-100 cm deep around Nelson and 50-80 cm deep around Rossland and other western parts of the region. The layers are composed of feathery surface hoar and sugary faceted grains and they overlie a hard melt-freeze crust.Â
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Be especially cautious as you transition into wind affected terrain.
- Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.
Problems
Storm Slabs
Recent wind has varied in direction so wind loaded pockets of storm slab may be found on a variety of aspects. At lower elevations, storm slabs will remain reactive where they sit over surface hoar.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Weak surface hoar and/or faceted grains sit above a melt-freeze crust 70 to 100 cm deep. Be aware that new snow and wind have been adding additional load to this layer, and it may become reactive again.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 4th, 2021 4:00PM
