Avalanche Forecast

Issued: Feb 5th, 2017 4:40PM

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

jsmith, Avalanche Canada

South Coast Inland.

Touchy storm slabs reactive to human triggers. Smaller storm slabs may step-down to deeper weak layers, resulting in large, destructive avalanches.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Monday: Mix of sun and cloud / Light, southwest winds / Freezing level sea level.Tuesday: Mix of sun and cloud / Light, southwest winds / Freezing level sea level.Wednesday: 5-10 cm new snow/ Moderate to strong, southwest winds/ Freezing level 250 m.

Avalanche Summary

Storm slabs are likely reactive to human triggers, especially on leeward slopes that are more wind loaded. In shallow snowpack areas to the north, storm slabs could potentially step-down to deeper weak layers.

Snowpack Summary

35-50 cm(lower amounts in the north) of recent storm snow has buried a wide variety of old snow surfaces including stiff wind slab or wind effected snow at upper elevations, sun crust on steep southerly slopes, surface hoar and surface facets in sheltered locations. The mid-January surface hoar and facet interface is now buried 50-80 cm and the mid-December facets down 90-120 cm remain a concern especially in shallower snowpack areas like the Duffey, Hurley and/ or South Chilcotins. These deeper weaknesses warrant monitoring especially through periods of more load. In southern areas (Coquihalla), the lower snowpack is reportedly well settled(stronger), than it is to the north.

Problems

Storm Slabs

Touchy storm slabs reactive to human triggers. Use small slopes with low consequence to test the bond of the storm snow.

Watch for signs of instability such as whumpfing, shotting cracks, or recent natural avalanching.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

This problem is more prevalent in the far north areas of the region and is a low likelihood, high consequence scenario that will need to be monitored as snow loads increase.

Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Feb 6th, 2017 2:00PM