Avalanche Forecast
Issued: Apr 9th, 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
Watch for areas of wind-drifted snow, especially near ridge-crests, roll-overs, and in steep terrain, and minimize your exposure to cornices.
Summary
Confidence
Weather Forecast
Friday night: Partly cloudy, isolated light flurries, moderate wind becoming northwest, treeline temperatures near -12 C, freezing level dropping to valley bottom.
Saturday: Mix of sun and cloud, moderate west wind, treeline temperatures near -6 C, freezing level reaching 700 m and dropping to valley bottom overnight.
Sunday: Mainly sunny, light northwest wind, treeline temperatures near -2 C, freezing level rising to 1000 m and dropping to valley bottom overnight.
Monday: Sunny with afternoon cloud, moderate winds becoming southeast, treeline temperatures near 0 C, freezing level rising to 1300 m.
Avalanche Summary
Since Monday, operators have reported small (size 1) natural and human triggered wind slabs on north and northeast aspects in the alpine.
Snowpack Summary
The region picked up 5-15 cm of new snow on Friday accompanied by periods of moderate south wind. The new snow adds to the incremental accumulations of up to 10 cm from earlier in the week that have been forming fresh wind slabs in lee features. These wind slabs may be up to 40 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.
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.
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
Up to 20 cm of recent snow from the past week and periods of strong wind have formed wind slabs in lee features that may be possible to trigger.
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 10th, 2021 4:00PM
