Avalanche Forecast

Issued: Mar 9th, 2015 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Wind slabs are becoming more reactive in recent days. Generally poor ski quality, but fast travel and long days for those extended tours. Plan your trip to avoid sun-exposed slopes in the afternoon as we transition to Spring.

Summary

Confidence

Good

Weather Forecast

A mix of sun and cloud is expected on Tuesday with mild temperatures. Freezing levels should reach near 2000m. Winds will be out of the west at 30km/h at ridge top.

Avalanche Summary

On Saturday a skier triggered a size 2.0 full depth slide on a steep and shallow south aspect at 2700m. No injuries or burial, but the skier was carried approximately 400m down slope. The last 48 hours have seen an increase in wind slab activity as well. These have all been small, thin wind slabs triggered either naturally or by skiers in the alpine and open areas at treeline. Typically the trigger zones are steep and unsupported features.

Snowpack Summary

Widespread wind affect in alpine and open areas at treeline. Prominent in these areas are hard wind slabs, soft wind slabs, and breakable wind crusts. Reverse wind loading is also evident due to a recent wind event from the north.Â Sun crusts are dominant on solar aspects. The ski quality is reasonable on polar aspects below 2300m if you can find an area without tracks. The November facet/depth hoar layer is a live and well and has been responsible for a recent skier-triggered avalanche. See avalanche activity.

Problems

Deep Persistent Slabs

Shallow snowpack areas that are steep should be treated with respect. These features are the most likely to steep down to basal weak layers and produce a full-depth avalanche. Large triggers such a s cornices are also a concern.

Choose well supported terrain without convexities.>Be aware of thin areas that may propogate to deeper instabilites.>Cornices become weak with daytime heating, so travel early on exposed slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Wind Slabs

Wind slabs are now widespread in the alpine and open areas at treeline and exist on all aspects. Some recent natural and skier-triggered avalanche activity is associated with this problem.

Caution in lee and cross-loaded terrain near ridge crests.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Loose Wet

Spring is here and solar heating will cause a de-stabilization of sun-exposed slopes, particularly in the afternoon.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 10th, 2015 2:00PM