Avalanche Forecast
Issued: Apr 11th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Cornices and Loose Wet.
JSmith,
Avalanche Canada
Lingering wind slabs may remain reactive to human triggers on lee features below ridgetops in the alpine. Use caution when transitioning into wind affected terrain and avoid slopes with large cornices overhead.
Summary
Confidence
Weather Forecast
SUNDAY NIGHT: Clear / Light, north ridgetop wind / alpine low temperature -13 / Freezing level valley bottom.
MONDAY: Sunny / Light, southwest ridgetop wind / alpine high temperature 0 / Freezing level 1400 m.
TUESDAY: Mix of sun and cloud / Moderate, west ridgetop wind / alpine high temperature 2 / Freezing level 2000 m.
WEDNESDAY: Sunny / Light, southwest ridgetop wind / alpine high temperature 7 / Freezing level rapidly rising to 2600 m.
Avalanche Summary
Naturally triggered wind slabs on northeasterly aspects in the alpine up to size 2 were reported on Saturday. Additionally, small (size 1) wet loose avalanches on solar aspects were reported at all elevations.
Snowpack Summary
5-20 cm. of recent snow was accompanied by periods of strong winds from shifting directions which formed wind slabs on a variety of aspects at treeline and above. Recent snowfall amounts will vary widely throughout the region due to the convective nature of the spring weather.
The recent snow has covered a variety of snow surfaces, including wind affected snow, crusts on solar aspects and at lower elevations, and soft snow on sheltered slopes at upper elevations.
Cornices are large, looming, and capable of triggering large avalanches when they fail.
The lower snowpack is reported as well settled and strong in most areas. However, weak facets exist at the base of the snowpack in the more shallow snowpack zones across the region. Where it exists, this layer has the potential to be triggered on steep, rocky slopes with a shallow or thin to thick snowpack; especially with large loads such as a cornice fall.
Terrain and Travel
- Avoid lee and cross-loaded terrain.
- Avoid exposure to slopes that have cornices overhead.
- Minimize exposure to sun-exposed slopes when the solar radiation is strong.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
Problems
Wind Slabs
Lingering wind slabs formed by 10-20 cm. of recent snow and previously strong winds from shifting directions may remain reactive on lee features in the alpine.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Cornices
Cornices are large and looming along many ridgelines and have likely grown with the recent wind.
Strong solar radiation and warming are common triggers for cornice failures which could trigger large avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Small wet loose avalanches may start to run naturally on steep solar aspects when the sun comes out.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Apr 12th, 2021 4:00PM
