Avalanche Forecast

Issued: Jan 6th, 2014 8:32AM

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

jlammers, Avalanche Canada

South Coast.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

Tuesday: Light snowfall / Moderate southwest winds / Freezing level at 800mWednesday: Moderate snowfall / Moderate to strong southwest winds / Freezing level at 1000mThursday: Light snowfall / Light winds / Freezing level at 1000m

Avalanche Summary

Two size 2.0 natural slab avalanches that were about 50 cm deep released on South aspects above the highway in the Duffey Lake area. These avalanches released during warm temperatures and direct solar exposure.

Snowpack Summary

Snowpack depths at treeline range from 130-170 cm in the South of the region, and from 80- 130 cm in the North of the region. The recent storm snow has settled down to about 15 cm in the Coquihalla and is reported to be bonding well to the old surface; however, easy shears may be found in the storm snow where it was transported into a soft wind slab. In the Duffey lake area the recent storm snow is reported to be bonding to a thin crust. Previously sun-exposed slopes are most likely sporting a melt-freeze crust. Below the recent storm snow, weak layers of buried surface hoar are producing moderate/sudden collapse test results down 25-35 cm. The snowpack in the north of the region has been described as "unusually facetted and low density."

Problems

Wind Slabs

Recent storm snow and strong winds have created pockets of wind slab in the alpine and at treeline. Wind slabs may extra touchy where they overlie weak "sugar snow" in shallow areas.

Use ridges or ribs to avoid pockets of wind loaded snow.>Be careful with wind loaded pockets near ridge crests and in terrain depressions>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Weak layers of buried surface hoar, crusts, and depth hoar may continue to be triggered by light additional loads like skiers and riders.

Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.>Use caution in shallow snowpack areas where triggering is more likely.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Jan 7th, 2014 2:00PM