Archived

Avalanche Forecast

Feb 3rd, 2017–Feb 4th, 2017

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

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

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 Rockies.

There is a lot of uncertainty with snowfall amounts through the period. There is good potential for amounts to exceed what is forecast in parts of the region. If that is the case, expect danger ratings to be higher than indicated.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Saturday: Mainly cloudy with flurries, accumulation 5cm / Light east wind / Alpine temperature -18Sunday: Flurries, accumulation 5-10cm / Light east wind / Alpine temperature -16Monday: Periods of snow, accumulation 15-25cm / Light to moderate southeast wind / Alpine temperature -11More details can be found on the Mountain Weather Forecast.

Avalanche Summary

No new avalanches have been reported. The main concern continues to be the possibility of triggering the weak faceted layers deeper in the snowpack.

Snowpack Summary

Taking regional variations into consideration, 5-10cm of new snow may overlay wind-affected surfaces at higher elevations. Below 1500 metres you may find an isolated thin breakable rain crust about 1 cm thick. The snowpack is quite variable throughout the region. In deeper areas, the snowpack appears to be well settled with isolated concerns about the mid-December facet layer buried 50-100 cm deep. In shallow snowpack areas and lower elevations, the snowpack is weak and faceted. For instance, in the Elk Valley north area near Crown Mountain last week the height of snow was 90 cm with foot penetration of 80 cm; or almost to ground. In these areas, the wind has formed isolated hard slabs above weak facets and created the potential for large persistent slab avalanches.

Avalanche Problems

Wind Slabs

Wind slabs may still be reactive to the weight of a person.

Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2

Deep Persistent Slabs

Triggering deeper weak layers remains possible where hard slabs sit above weak sugary snow. This is most likely in thin snowpack parts of the region.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Danger exists where denser snow overlies weak, sugary snow below.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3