Avalanche Forecast
Dec 20th, 2018–Dec 21st, 2018
Alpine
3:
Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3:
Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3:
Considerable
The avalanche danger rating below treeline will be considerable
Alpine
3:
Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3:
Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2:
Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3:
Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3:
Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2:
Moderate
The avalanche danger rating below treeline will be moderate
Regions: Kootenay Boundary.
Clearing skies may entice us to bigger slopes, but it is a good time to remain conservative; recent storm slabs overly a touchy weak layer.
Confidence
High.
Weather Forecast
THURSDAY NIGHT: Cloudy with light snowfall, freezing level dropping from 1300m to below valley bottom. FRIDAY: Clearing over the day, moderate to strong northwest winds, alpine temperature -11°c, freezing level below valley bottom. SATURDAY: Partly cloudy, moderate southwest winds, alpine temperature -9°c, freezing level below valley bottom. SUNDAY: Cloudy with light snowfall, accumulation 5 to 10cm, moderate southwest winds, alpine temperature -5°c, freezing level below valley bottom.
Avalanche Summary
Large (size 2 to 3) slab avalanches were triggered naturally, by skiers, and explosives on Tuesday and Wednesday. The avalanches were generally 50 to 70cm deep and either within the storm snow or on the weak layer described in the snowpack discussion.
Snowpack Summary
Around 50 to 100cm of recent storm snow overlies a rain crust and a weak layer of feathery surface hoar and sugary facets. Avalanche activity, remote triggering, and snowpack test results tell us that it is a critical layer. It is best to travel extremely cautiously with this layer in the snowpack.The lower snowpack is well-settled.
Avalanche Problems
Persistent Slabs
A weak layer buried around 50 to 100 cm is the primary concern. This weak layer has recently produced large avalanches. Shallower storm slab avalanches could step down to this layer and produce larger avalanches.
Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.Choose low-angle terrain without overhead exposure and watch for clues of instability.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 3
Storm Slabs
The storm snow from Thursday may not bond well to previous surfaces. Expect to find the deepest slabs in lee terrain features, as strong southerly winds accompanied the storm.
Use caution in lee areas. Recent wind loading have created wind slabs.Stick to simple terrain and be aware of what is above you at all times.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 2