Avalanche Forecast

Issued: Jan 8th, 2019 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Take the time to dig down and evaluate the snowpack before committing to a line. There are several buried layers of concern, principally the very weak basal layers.

Summary

Confidence

High -

Weather Forecast

Weather models are disagreeing about the extent of possible precipitation for Wednesday. Some models are calling for up to 8cm, while others are predicting only a trace of new snow. There is consistency in the temperature and wind predictions with highs of -3 Celsius and strong to extreme SW winds expected.

Avalanche Summary

One size 2.0 naturally triggered slab avalanche was observed today. This slab occurred at 2600m on a NW aspect in the past 24hrs, likely triggered by wind loading.

Snowpack Summary

An additional 2cm of new snow fell overnight. The upper snowpack consists of mostly low density surface snow with ski penetrations around 30cm. However, wind slabs are noticeable at Treeline elevations and get progressively more dense and widespread across the terrain as you gain elevation. In most cases the bond below these wind slabs seems to be relatively good, but convex and unsupported terrain should be approached cautiously. Forecasters are watching a few persistent weak layers deeper in the snowpack that continue to give results in stability tests. The layers to watch for include the Dec 30th facet interface (down 50cm), the Dec 10th surface hoar/facet interface (down 70cm) and the extensive basal facets which make up the entire bottom half of the snowpack.

Problems

Wind Slabs

Watch for slabs as you approach Treeline elevations. Convexities and unsupported terrain are areas of concern.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Avoid freshly wind loaded features.Avoid convexities or areas with a thin or variable snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

The bottom half of the snowpack is very weak. Triggering this layer will result in large to very large avalanches.

Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.Remote triggering is a concern, watch out for adjacent slopes.Carefully evaluate and use caution around thin snowpack areas.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Valid until: Jan 9th, 2019 2:00PM