Avalanche Forecast

Issued: Feb 23rd, 2016 8:00AM

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

Parks Canada ian gale, Parks Canada

The sun should be out today! With this heat the Wind and Storm slabs will become reactive. Limiting exposure to overhead hazards like sunny start zones and cornices are key.

Summary

Weather Forecast

Today we'll start to feel the effects of the high pressure system that will be in place until the weekend. Today will be cloudy with sunny periods, alpine high of -6, freezing level to 1100m & light ridge wind gusting to 30km/hr.With the first kiss of sun on Sunday the slopes became sensitive quickly. Keep this in mind when the sun appears

Snowpack Summary

10 cms of new snow fell yesterday burying wind slab in the Alpine and at treeline. This low density snow was easily moved by light/mod winds creating new soft slabs, expect both these wind slabs to still be sensitive to human triggering. Storm slabs are still showing easy shears. The Feb 10 surface hoar is dn 60-100cm and may still be triggered.

Avalanche Summary

Without the direct heat from the sun yesterday natural avalanche activity decreased. On the 21st there was a skier triggered sz 1.5 on Little Sifton col, the skier was involved but uninjured. The slide was 25cm deep, 50m wide & ran 70m. There was also BIG (up to sz 4)avalanches in the Asulkan &Loop valleys from cornices failing during solar warming

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs
Touchy windslab in the immediate lee of ridgelines and crossloaded features formed Fri from mod S winds (the skier triggered slide on Sifton col is a good example). This older wind slab is now buried under a new soft Wsl from yesterdays snow and wind
If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

An icon showing Storm Slabs
Storm slabs may be sensitive to human triggering given the right terrain feature. Steep planar slopes should be investigated before jumping in. Avoid unsupported or convex terrain.
If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs
Feb 10 interface lingers and is becoming difficult to forecast. In some areas there is surface hoar on a crust which is a good recipe for bad avalanches. It may become reactive given prolonged sun or added load such as cornice fall or slab avalanche
Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 24th, 2016 8:00AM