Archived

Avalanche Forecast

Feb 19th, 2018–Feb 20th, 2018

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

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

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

Regions: Kananaskis.

Widespread wind slabs in the alpine and isolated wind slabs at tree line are still a concern for triggering avalanches. The deeper weak layers are also a concern for the mere fact that they would produce big avalanches.

Confidence

Weather Forecast

The weatherman says that Tuesday will be a mix of sun and cloud with isolated flurries. I think that covers all the bases. Winds should be light with an alpine temperature of -19c.The rest of the week is looking like a mix of sun and cloud with cold alpine temperatures(-20c). Might be a good idea to choose trips which stay in the sun.

Avalanche Summary

No new avalanche activity was observed.

Snowpack Summary

The wind slabs from last week's wind event are under the recent 5-10cm of snow. They are extensive in the alpine and variable at tree line depending upon the drainage. Forecasters are still concerned for triggering these wind slabs 20-40cm down. Secondly, large natural avalanches were still occurring on Feb 16 failing on the deeper persistent layers 100-150cm down(Dec 15 facets and Jan 6 surface hoar). We are still apprehensive to venture out into bigger terrain or travel under large avalanche slopes.

Avalanche Problems

Wind Slabs

Widepsread windslabs in Alpine terrain and more variable at treeline locations. Some areas there has been winds well down into the timber and others not so much.

Use caution in lee areas. Recent wind loading has created wind slabs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2.5

Persistent Slabs

Hard and sudden planar results are being observed on this layer down in general 120cm. Its getting harder to trigger but will result in large avalanches.

Dig down to find and test weak layers before committing to a line.Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible - Likely

Expected Size: 1.5 - 3

Deep Persistent Slabs

Recent avalanche activity has shown the potential for avalanches to step down to this layer.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3.5