Avalanche Forecast

Issued: Apr 6th, 2017 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

No freeze is forecast overnight and light rain is expected. Warm temps, rain and no freeze may all combine to wake up the basal weakness.

Summary

Confidence

Moderate - Freezing levels are uncertain on Friday

Weather Forecast

Not much of a freeze is expected overnight and the light rain (at lower elevations) and snow above 2300m is forecast to continue overnight and through the day on Friday. Temps are forecast to climb above zero at 2500m so we may see the heat wake up some of the basal layers in areas that have not released. Ski quality will not likely be all that great on friday and it may be worth taking a pass in many areas until we get a good freeze.

Avalanche Summary

No new slab avalanche activity was observed but there were numerous loose wet slides up to sz 1.

Snowpack Summary

Rain up to 2300m on Thursday with light flurries above this elevation. There was a very minimal freeze overnight on Wednesday and as a result, the top 10-20cm of the snow is wet. Above 2300m there is a widespread crust on solar aspects up to 2600m. Northern aspects are still holding dry snow but we have certainly transitioned into the time wherein if you want dry snow, you must be on a true north aspect. The windslabs seem to be only found in isolated alpine areas but we are still getting moderate sudden collapse sheers in the basal facets down 150-180cm. Pin wheeling was observed on all aspects up to 2500m so ski quality is taking a turn for the worse.

Problems

Loose Wet

No freeze is expected below 2400m over the next 24hrs. Light rain is also forecast. Loose wet slides may trigger deeper slabs failing on the basal facets.

Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.Use extra caution on solar slopes or if the snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Wind Slabs

Expect to encounter these slabs along ridgelines and in crossloaded features in Alpine terrain.

Avoid cross loaded slopes at or above treeline.Use caution in lee areas. Recent wind loading has created wind slabs.Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

We know it sounds like a broken record, but this deep layer is still a threat in any avalanche terrain that has not yet had extensive previous avalanching. While there is a lower probability of triggering, the consequences are high.

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Be wary of slopes that did not previously avalanche.Pay attention to overhead hazards like cornices which could easily trigger deep slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Apr 7th, 2017 2:00PM