Archived

Avalanche Forecast

Jan 18th, 2013–Jan 19th, 2013

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: South Columbia.

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Saturday: Moderate W winds. Alpine temperature near -2. No snow.Sunday: Light to moderate W winds. Alpine temperature near -2. No snow.Monday: Light SW winds. Alpine temperature near -2. No snow.

Avalanche Summary

A couple of large glide slab releases have been observed. Otherwise, no new avalanches have been reported.

Snowpack Summary

Strong NW through SW winds have left wind slabs in many areas, even at treeline. These are likely to be gaining strength as time goes on and the amount of snow available for transport diminishes. Around 40-60 cm settled storm snow sits above surface hoar (found especially at and below treeline in sheltered areas), a sun crust (on steep S to SW -facing slopes) and facets. The distribution of these weaknesses is patchy, but where they exist, it may still be possible to trigger a large avalanche with the weight of a person or snowmobile. Test results on these interfaces vary from no result to moderate, sudden results. A strong mid-pack overlies a weak facet/crust layer near the base of the snowpack, which is generally considered inactive.

Avalanche Problems

Wind Slabs

Wind slabs may be found behind terrain breaks such as ridges and ribs. It may be possible for a wind slab to step down to a deeper instability.

Be aware of the potential for wide propagations due to the presence of hard windslabs.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4

Persistent Slabs

Triggering persistent slabs is becoming less likely, but a cautious approach to steep south-facing slopes and sheltered terrain below treeline is still advised.

Dig down to find and test weak layers before committing to a line.>Be aware of thin areas that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely - Possible

Expected Size: 1 - 5