Avalanche Forecast
Issued: Apr 8th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Cornices.
astclair,
Avalanche Canada
Avoid freshly wind-loaded features, especially near ridge-crests, roll-overs, and in steep terrain, and minimize exposure to cornices.
Summary
Confidence
Low - Forecast precipitation (either snow or rain) amounts are uncertain.
Weather Forecast
Thursday night: Cloudy, 5-10 cm of snow, strong southwest wind, treeline temperatures near -8 C, freezing level dropping to valley bottom overnight.
Friday: Mainly cloudy, scattered flurries with up to 5 cm of accumulation, moderate southwest wind, treeline temperatures near -4 C, freezing level rising to 800 m and dropping to valley bottom overnight.
Saturday: Increasing cloud, moderate west wind, treeline temperatures near -4 C, freezing level reaching 500 m and dropping to valley bottom overnight.
Sunday: Mix of sun and cloud, light west wind, treeline temperatures near -1 C, freezing level rising to 1000 m and dropping to valley bottom overnight.
Avalanche Summary
Since Monday, operators have reported small (size 1) natural and human triggered wind slabs on north and northeast aspects in the alpine. With new snow and wind in the forecast, wind slabs have the potential to be more reactive and more consequential.
Snowpack Summary
An incoming storm is expected to bring 5-15 cm of new snow by Friday afternoon accompanied by strong southwest winds. The new snow will add to fresh wind slabs that have been forming throughout the week from incremental accumulations and that may be up to 30 cm deep in some areas.
The recent snow has covered a variety of previous snow surfaces, including widespread wind-affect and a crust on steep south-facing slopes and at lower elevations. Cornices are large and looming at this time of year.Â
Buried 70-120 cm deep, a spotty layer of surface hoar may exist on sheltered north aspects, but no recent avalanches have been reported on this layer.Â
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
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Minimize your exposure time below cornices.
Problems
Wind Slabs
New snow and strong wind are expected to contribute to ongoing wind slab formation in lee features. Avoid freshly wind-loaded terrain features.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are large and looming along many ridgelines and have likely grown with the recent wind.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 9th, 2021 4:00PM
