Avalanche Forecast

Issued: Mar 30th, 2017 3:00PM

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

Alberta Parks mike.koppang, Alberta Parks

Stability will deteriorate quickly when the sun comes out so be aware of overhead terrain and the aspect. Early starts and finishes are key. Good skiing is being found on northern aspects!

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Friday

Weather Forecast

Friday looks like a carbon copy of Thursday with a mix of sun and cloud, generally light NW winds and freezing levels around 2200m.  Important to note that when the sun comes out the solar radiation is intense and the stablity on the solar aspects will deteriorate quickly.  Keep an eye on the weather and overhead terrain as you travel.

Avalanche Summary

Some loose sluffing up to sz 1.5 out of steep solar terrain when the sun came out but otherwise, no new natural activity was observed.

Snowpack Summary

Convective squalls continue to give us 5-10cm/day but these amount can vary by the drainage and also taper rapidly at lower elevations. Windslabs are being observed in Alpine areas along ridgelines and in open terrain. These slabs are 20-30cm thick and are reactive to a skiers weight. At treeline the windslab are very isolated and more stubborn to trigger. Moist snow was observed on Solar aspects up to 2600m and on all aspects below 2100m.  Expect to encounter crusts in the upper snowpack on all aspects at lower elevations and on solar aspects up to 2600m. Despite no recent avalanche activity on the deeper weak layers, we consider the consequences of a large avalanche before committing to a slope.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs are present in the Alpine much more isolated at treeline. Though found on all aspects watch for thicker slabs in lee and cross-loaded terrain such as N and E aspects.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Avoid steep lee and cross-loaded slopes

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

An icon showing Cornices
Cornices are more fragile during sunny or warm periods. A cornice failure could trigger a significant slab on underlying slopes.
Cornices become weak with daytime heating. Pay attention to overhead hazards like cornices which could easily trigger deep slabs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Due to the nature of the snowpack, forecasters still have very little confidence in larger terrain features, particularly in the Alpine. Full depth avalanches that could reach the end of run out zones are still possible. If it hasnt slid, avoid it.
Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Mar 31st, 2017 2:00PM