Archived

Avalanche Forecast

Feb 16th, 2016–Feb 17th, 2016

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

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: Kananaskis.

North winds have reversed the typical loading pattern and have made windslabs in unusual places. On top of this, cornice growth has changed the overhead exposure risk. Take a good look around before setting off.

Confidence

High

Weather Forecast

We'll see a brief break in the winds tomorrow. They will average 20km/hr, but occasionally gust to 45. They are also expected to swing around to the SW overnight. The temp will be -1 in the alpine, with near zero temps expected valley bottom. The cloud cover will help limit the solar input.

Avalanche Summary

The south end of the Goat Range had 1 sz2.5 slab that released in the last 12 hours. 2500m, NE asp, initiated out of thin cliff bands and scrubbed to ground low in the start zone. Re-loading from the wind has essentially erased all evidence of yesterday's cycle.

Snowpack Summary

Wind is the story with our snowpack. Even below treeline has seen some wind affect in the last 24-36hrs. In many areas the crust has been blown clean and is back on the surface. In sheltered areas, expect the Feb 11th crust to be down 10-15cm. Treeline is either wind scoured or new, reverse loaded windslabs. There are still sheltered areas just below treeline with good snow, but the north winds have made them few and far between. In sheltered areas the feb 11th crust is down 20-30cm with new windslabs sitting on top. The alpine elevations have seen sustained north/northwest winds that have created widespread windslabs.

Avalanche Problems

Wind Slabs

Any open area at treeline and alpine elevations has the distinct wavy appearance that suggests widespread windloading. Expect slabs to exist well below ridgelines and avoid any large features.

Avoid freshly wind loaded features.>Caution in lee and cross-loaded terrain near ridge crests.>

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

Elevations: Alpine, Treeline.

Likelihood: Likely - Very Likely

Expected Size: 2 - 4

Persistent Slabs

Despite somewhat encouraging test results, we still don't trust this layer. Especially as the load increases (locally through windloading). This layer may cause large, unexpected avalanches. Large triggers should also be considered.

Pay attention to overhead hazards like cornices.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 5