Avalanche Forecast

Issued: Mar 1st, 2017 3:20PM

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

Alberta Parks matt.mueller, Alberta Parks

In theory we are using the ratings by the exact definition. In practice, we are treating it as a cautious moderate. Keep a close eye on the snow and your terrain choice despite the moderate rating.

Summary

Confidence

High -

Weather Forecast

The winds will continue overnight. Westerly ridge winds will be sustained at  50km/hr at ridgeline and tomorrow range from 40-60km/hr. The 2500m high temp will be -9. As for precip, only trace amounts are expected, but there may be higher localized amounts.

Avalanche Summary

One notable avalanche was seen pouring off an alpine face today. Undoubtedly the wind is to blame, whether it was a cornice collapse or loose dry is a mystery. It appeared to pull out the slope below the face. Sz2, Goat Range, East aspect and went into skiable terrain.

Snowpack Summary

The winds picked up last night and created new windslabs on north to south aspects. These start to show up at treeline and continue up to alpine elevations. In the high alpine the winds were/are strong enough to strip the snow completely. Lots of wind transport indicates that immediate lee terrain and cross loaded gullies will be primed. Treeline and below has felt the cold. Facetting has weakened existing slabs and has started to break down the various crusts from a week ago.

Problems

Wind Slabs

An icon showing Wind Slabs
New wind slabs are on N-S aspect. At treeline, these tend to be more widespread but less dense. In the alpine, the wind has focused them to immediate lee. This problem also factors in buried windslabs that are down 10-20cm.
Avoid lee and cross-loaded terrain near ridge crests.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Persistent Slabs

An icon showing Persistent Slabs
The cold weather has helped to break down the surface slabs, however the buried hard slab and/or facet layer is still intact. Convex terrain at treeline seems to be the most troubling areas.
Be aware of the potential for wide propagations.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Recent facetting has broken down the surface slabs below treeline. Above that, this problem is alive and well! It is a hard layer to trust.
Avoid steep convexities or areas with a thin or variable snowpack.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Mar 2nd, 2017 2:00PM