Avalanche Forecast

Issued: Apr 10th, 2013 10:24AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include 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

Thursday: Light snow. Moderate to strong NW winds. Freezing level around 1600 m. Friday: Moderate snow, mainly in the afternoon. Moderate to strong SW winds. Freezing level around 1300 m.Saturday: Light to moderate snow. Light W winds. Freezing level around 1400 m.

Avalanche Summary

Most of the recent avalanche activity has been on high elevation north aspects. Natural and human-triggered (including remotely triggered) slabs failed on surface hoar or storm snow weaknesses during and after last weekend’s storm. A natural avalanche cycle is expected to have occurred on Wednesday, but so far we have no reports from the field.

Snowpack Summary

Additional storm snow has added to an existing storm slab problem above about 2000 m. Winds from the SW through to NW are likely to have created new wind slabs and added to cornices. A buried surface hoar interface is now buried within the upper metre or so of the snowpack, mainly on high-elevation northerly aspects. It may be slowly gaining some strength, but these slopes should still be treated with suspicion. At lower elevations, rain-soaked snow may be weak when wet.

Problems

Storm Slabs

New snow and wind have created storm slabs at high elevations. This problem is of most concern on wind-loaded slopes, and on high-elevation northerly aspects, where a buried layer of surface hoar may create surprisingly large avalanches.

Avoid freshly wind loaded features.>Avoid steep slopes below cornices.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 5

Loose Wet

Loose wet avalanches and glide slabs may be especially prone to triggering at low elevations.

Avoid exposure to terrain traps where the consequences of a pushy wet avalanche could be serious.>Watch for wet loose or slab activity with forecast rain and/or warm temperatures.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Apr 11th, 2013 2:00PM