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 at treeline and above. Expect natural wet loose avalanches to occur on solar aspects if the sun comes out.
Summary
Confidence
Weather Forecast
SUNDAY NIGHT: Mostly cloudy with convective flurries; 5-15 cm. / Light, southeast ridgetop wind / alpine low temperature -10 / Freezing level valley bottom.
MONDAY: Mix of sun and cloud / Light, northeast ridgetop wind / alpine high temperature -1 / Freezing level 1500 m.
TUESDAY: Mostly sunny / Light, northeast ridgetop wind / alpine high temperature 0 / Freezing level 1500 m.
WEDNESDAY: Mostly sunny / Moderate, northeast ridgetop wind / alpine high temperature 1 / Freezing level 1700 m.
Avalanche Summary
Explosive triggered dry loose and slab avalanches up to size 1.5 were reported on Saturday.
Snowpack Summary
Lingering wind slabs formed by 30-40 cm. of recent snow and previously strong southwesterly winds may remain reactive on lee features 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 is sitting on hard crusts on solar aspects and a mix of wind affected or soft surfaces on shady aspects.
Cornices are large, looming, and capable of triggering large avalanches when they fail.
The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack that may become a concern when the next big warm-up arrives.
Snow line is slowly creeping up the mountains to roughly 1400 m in elevation. Check out this MIN report for more details on the access from common staging areas.
Glide cracks releasing as full depth glide slab avalanches become more common in the spring and are extremely difficult to predict. Best practice is to avoid slopes with glide cracks.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid freshly wind loaded terrain features.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
Problems
Wind Slabs
Lingering wind slabs formed by 30-40 cm. of recent snow and previously strong southwesterly winds may remain reactive on lee features at treeline and above
Aspects: North, North East, East, South East, 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.
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
Expect natural wet loose avalanches to occur on solar aspects if 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
