Archived

Avalanche Forecast

Jan 17th, 2015–Jan 18th, 2015

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

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

3: Considerable

The avalanche danger rating at treeline will be considerable

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

1: Low

The avalanche danger rating below treeline will be low

Regions: Banff Yoho Kootenay.

With new snow, warming temperatures and strong W winds forecast for Sunday afternoon, it will be important to watch the local snowfall amounts and wind loading in the areas you are traveling in and reduce your exposure as the hazard increases.

Weather Forecast

A storm is forecast to arrive by mid day on Sunday bringing 10-20cm of new snow and very strong West winds at ridge top near the divide. Less snow is forecast in eastern areas. The winds ease off a little on Monday and switch to the NW with a few more cm`s of snow forecast for Monday and Tuesday. Treeline temperatures remain between -4 and -10`C.

Snowpack Summary

A trace of new snow over facets, surface hoar, or sun crust on steep South slopes. The snowpack is generally weak and facetted throughout. The Dec 18 interface is evident down 20-40 cm and is still a concern in deeper snowpack areas. In shallower areas the slab above this has facetted out. Wind slabs exist in many open areas above tree line.

Avalanche Summary

No natural avalanche activity observed in past 72 hrs.

Confidence

Intensity of incoming weather systems is uncertain on Sunday

Avalanche Problems

Wind Slabs

New snow and strong W winds tomorrow afternoon will create wind slabs in open areas at tree line and above. Ice climbers should watch for sluffing in steep gullies as the new snow arrives.

Minimize overhead exposure during periods of heavy loading from new snow, wind.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Persistent Slabs

Keep an eye on this layer as the new snow arrives. In shallower snowpack areas this layer has been facetting out. In deeper areas where a stronger slab exists above this layer it is more of a concern.

Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Deep Persistent Slabs

In shallower snowpack areas (most of the region) the weak base of the snowpack persists and could be triggered in steep, rocky terrain features. This problem will persist for some time, give it careful consideration before entering serious terrain.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 3