Avalanche Forecast

Issued: Mar 25th, 2014 8:00AM

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

ali haeri, Parks Canada

Glacier.

Moderate hazard indicates that small and large avalanches are still possible. Cloud cover is expected to increase today but if the sun stays out the hazard will rise.

Summary

Weather Forecast

Pacific low off the coast has produced a front that will be arriving to the interior with light to moderate amounts of precipitation this afternoon. Winds to remain generally light from the south west and freezing level to rise to 1400m.

Snowpack Summary

Aspect dependant, north and east will have settling snow, south and west will have a surface crust and the Mar 22 crust down 10cm. The Mar 13 crust down 45-65 and the Mar 2 CR/SH layer down 1m. Tests show hard sudden result on the Mar 2 layer, propagation tests still show large potential for propagation. The Feb10 layer is down ~2m.

Avalanche Summary

Yesterday saw numerous solar triggered loose natural avalanches in the highway corridor and in the backcountry to size 3.0. On Sunday Cheops North 4 (above Connaught creek), north aspect, ~2500m ran naturally size 2.0. From Friday in Grizzly Bowl, east aspect, ~2600m, size 3.5 showing wide propagation possibly cornice triggered.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Persistent Slabs

The early March weak layer down ~1m is reactive in snowpack tests with hard sudden results. We still see sporadic large avalanche events that fail on this layer. Choose supported slopes that have uniform snow cover.

Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Deep Persistent Slabs

Deeper in the snowpack is the February surface hoar crust layer. Large triggers, such as heavy snowfall or cornice fall will be needed to get this layer to fail.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 4

Valid until: Mar 26th, 2014 8:00AM