Archived

Avalanche Forecast

Feb 4th, 2017–Feb 5th, 2017

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: South Coast Inland.

Touchy storm slabs reactive to human triggers. Conservative decision making will be CRITICAL to playing safe in the mountains this weekend.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

Saturday night: 20-25 cm new snow / Moderate to strong, southwest winds / Freezing level sea level.Sunday: 0-5 cm new snow / Moderate, southwest winds/ Freezing level sea level.Monday: Mostly cloudy with flurries / Light to moderate, southwest winds / Freezing level sea level.Tuesday: Mix of sun and cloud / Light, southwest winds/ Freezing level sea level.

Avalanche Summary

New storm slabs will likely have a poor bond to the old snow surfaces and be reactive to human triggers, especially on leeward slopes that are more wind loaded. In thin areas to the north, storm slabs could potentially step-down to deeper weak layers.

Snowpack Summary

15-25 cm of new 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. An additional 20-25 cm of new snow is expected by Sunday morning, bringing storm totals up to 35-50 cm(lower amounts in the north). 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.

Avalanche Problems

Storm Slabs

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

The new snow will require several days to settle and stabilize.Use conservative route selection, choose moderate angled and supported terrain with low consequence.Watch for signs of instability such as whumpfing, shotting cracks, or recent natural avalanching.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 3

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