Avalanche Forecast

Issued: Apr 11th, 2013 10:39AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Cornices.

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Friday: Light snowfall during the day intensifying to moderate in the late afternoon / Moderate southwest winds / Freezing level at 800mSaturday: Light snowfall / Light southwest winds / Freezing level at 1000mSunday: Possible sunny breaks / Light northeast winds / Freezing level at 1300m

Avalanche Summary

Observations were limited on Wednesday; however, explosives control produced slab avalanches to size 2 which formed in response to strong winds and rapid loading. On Thursday a size 2 slab was ski cut on a northeast aspect (unknown elevation). The bed surface was the early April temperature crust.

Snowpack Summary

Moderate amounts of snow fell on Wednesday. In the south of the region, heavy accumulations (~40cm) were observed. At lower elevations rain continued to saturate the snowpack. The storm was accompanied by moderate to strong south/southwest winds which left variable snow distribution in exposed terrain with dense wind slabs forming in lee and cross-loaded features. Up to 85cm below the surface you will likely find a melt-freeze crust from last week's sunny weather. At the same interface, you may find spotty surface hoar on high north facing terrain. Large natural activity and remote triggers from earlier in the week suggest the surface hoar may continue to be reactive, especially with the weight of the new snow. Cornices are very large and could pop off with continued mild temperatures.

Problems

Storm Slabs

An icon showing Storm Slabs
Recently formed storm/ windslabs exist at treeline and above. Triggering is most likely in wind-affected terrain, or on steep unsupported slopes where buried crusts or surface hoar exist.
Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Carefully evaluate big alpine terrain by digging and testing on adjacent, safe slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 5

Cornices

An icon showing Cornices
Recent snow and wind has added mass to existing large and potentially destructive cornices.
Give cornices a wide berth when travelling on or below ridges.>Pay attention to overhead hazards like cornices.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 6

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