Archived

Avalanche Forecast

Dec 19th, 2014–Dec 20th, 2014

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

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

2: Moderate

The avalanche danger rating below treeline will be moderate

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: Cariboos.

New snow, strong winds and rising temperatures make a good recipe for rising avalanche danger over the next few days.

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

Expect light to moderate snow from Saturday to Monday. Temperatures rise towards 0 at 1500m by Saturday. Winds are expected to be moderate to strong from the west to south-west throughout the period.

Avalanche Summary

Reports suggest that recent new snow is failing on the buried surface hoar and sluffing fast in steep terrain. In areas affected by wind, slabs may have formed above this weak interface. Explosives control on Thursday produced two size 2 avalanches in steep rocky alpine terrain. Several bombs produced no results.

Snowpack Summary

Storm snow is expected to bond poorly to a layer of large surface hoar. Below around 2100m, this surface hoar sits on a hard rain crust. Above 2100m the surface hoar sits on well settled and faceted snow. A thick rain crust with facets from early November is buried over 1 m down and may still be reactive in isolated areas.

Avalanche Problems

Storm Slabs

Building storm snow is expected to be shifted by winds into slabs on lee slopes. In more sheltered areas, loose snow avalanches are likely in steep terrain. The new snow sits above a weak layer of buried crystals.

Avoid freshly wind loaded features by sticking to ridges and ribs.>Be cautious of sluffing in steep terrain.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Deep Persistent Slabs

There is still the potential to trigger a deeply buried weak layer, resulting in a surprisingly large avalanche.

Remote triggering is a concern, watch out for adjacent slopes.>Avoid common trigger zones including thin snowpack areas, near rocky outcrops, and steep alpine slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 5