Avalanche Forecast

Issued: Apr 11th, 2013 10:45AM

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 to strong southwest winds / Freezing level at 1000mSaturday: Light snowfall / Light southwest winds / Freezing level at 1200mSunday: Possible sunny breaks / Light northeast winds / Freezing level at 1200m

Avalanche Summary

Avalanche observations have been limited in the last few days; however, 2 explosives controlled size 2.5 slab avalanches were reported from the Duffey Lake area. They occurred on a north facing alpine slope and ran 1000-1400m.

Snowpack Summary

Moderate to locally heavy amounts of snow fell on Wednesday. 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 areas near ridgetop with dense wind slabs forming in lee and cross-loaded features. Up to 75cm below the surface you will likely find a melt-freeze crust from last week's sunny weather. At the same interface, you may also find spotty surface hoar on some high, north facing slopes. Cornices are very large and could pop off with continued mild temperatures.

Problems

Storm Slabs

An icon showing Storm Slabs
Dense wind slabs have formed on slopes in the lee of ridge crests and in cross loaded features at upper elevations. In isolated terrain, storm snow avalanches may step down to a crust or surface hoar buried last week.
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