Avalanche Forecast

Issued: Apr 11th, 2013 9:38AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs.

Avalanche Canada ccampbell, Avalanche Canada

Summary

Confidence

Fair - Due to limited field observations for the entire period

Weather Forecast

Friday: Light to moderate snowfall with 10-15cm of accumulation, freezing levels as high as 800m, and strong southerly winds. Saturday and Sunday: A mix of sun and cloud with isolated light flurries, freezing levels as high as 1100m, but dropping to 500m overnight, light easterly winds gusting moderate with flurry activity.

Avalanche Summary

Reports from Wednesday include evidence of Tuesday's natural avalanche cycle with wind slab avalanches up to Size 2.5 failing within the storm snow on steep terrain features. One Size 3 cornice-triggered persistent slab avalanche stepped down to the surface hoar buried a month ago.

Snowpack Summary

15-35cm of recent snow is generally bonding well to the previous snow surface, which includes a crust, facets and/or surface hoar. Strong westerly winds created widespread hard and soft wind slabs in exposed areas, which are reactive to human triggers on steep wind-loaded rolls. Below treeline, the surface snow is undergoing daily melt-freeze cycles with the upper metre of snow becoming wet and cohesionless by mid-afternoon. Concerns remain for a patchy persistent weakness buried a month ago, and deeper in the snowpack, basal facets may become a concern with continued mild temperatures. Cornices are well-developed and could easily become unstable during periods of warm weather or direct solar radiation.

Problems

Wind Slabs

An icon showing Wind Slabs
Fresh thin wind slabs are lurking immediately downwind of ridge crests and exposed terrain features. They are susceptible to human triggering in steep terrain and heavy loading may cause natural avalanches.
Be cautious as you transition into wind affected terrain.>Avoid freshly wind loaded features.>Assess start zones carefully and use safe travel techniques.>

Aspects: North, North East, East, South East.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Apr 12th, 2013 2:00PM