Avalanche Forecast

Issued: Apr 8th, 2013 10:18AM

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

pgoddard, Avalanche Canada

South Columbia.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period

Weather Forecast

Tuesday: Light snow. Light W winds. Alpine temperature near -6. Wednesday: 25-35 cm snow. Strong to extreme SW winds. Alpine temperature near -3.Thursday: Light snow. Light SW wind. Alpine temperature near -4.

Avalanche Summary

An avalanche cycle of slabs up to size 3 occurred during the weekend’s storm. Many of these events were on NE-NW aspects above about 2400 m. A few skier-remote triggered slabs were also reported on Sunday. These either failed on a storm snow weakness, or on surface hoar buried below the storm snow. On sun-warmed and low elevation slopes, loose snow and glide avalanches continue to be reported.

Snowpack Summary

Recent storm snow (up to 50 cm in the far south) is sitting on a variable interface, consisting of a crust or moist snow; or a recently formed layer of surface hoar or facets, which is mainly found on high-elevation northerly aspects. In some locations the surface hoar/facet interface is touchy, with skier triggering likely. Winds have shifted storm snow into reactive slabs lee to south-easterly to south-westerly winds. Below treeline, the snow is in a spring melt-freeze regime, melting by day and freezing by night. Cornices are very large and loom as potential triggers for avalanches.

Problems

Wind Slabs

Wind slabs may be found near ridges and in gullies. The large cornices that loom over many slopes have the potential to fail and trigger avalanches.

Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>Give cornices a wide berth when travelling on or below ridges.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Storm Slabs

In some areas, new snow is bonding poorly at a weak interface. Skiers have been triggering slabs remotely, mainly on north-facing slopes at alpine elevations.

Dig down to find and test weak layers before committing to a line.>Choose well supported terrain without convexities.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Loose Wet

Watch for loose wet avalanches and glide slabs, which may fail naturally in response to rainfall at low elevations.

Avoid travelling on slopes which are becoming wet due to rain, warm temperatures, or sun.>Don't travel on or underneath slopes with glide cracks.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Apr 9th, 2013 2:00PM