Avalanche Forecast

Issued: Feb 26th, 2019 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

The last time it warmed up (about a week ago), the region experienced a bit of an avalanche cycle. Wednesday is expected to be mild, so watch localized conditions in case history repeats itself.

Summary

Confidence

High -

Weather Forecast

Wednesday will be the first milder we've had for quite some time, with temperatures reaching a relatively balmy -8. Light NE winds, no snow and generally sunny conditions can be expected. Late Thursday and into Friday some very light flurries are possible.

Avalanche Summary

Isolated natural slab avalanche activity has occurred in the past 24 to 48 hours on E and NE aspects in the Alpine. These slabs are associated with our current wind slab problem and are failing 40 to 50cm deep and running up to size 2.0.

Snowpack Summary

Widespread wind effect and wind slabs in the Alpine on all aspects (as long as the slope hasn't been blown down to rock). These slabs disappear quite quickly as you descend into Treeline. The prolonged and significant cold period continues to facet the snowpack at all elevations, which is particularly problematic in shallow snowpack areas and/or at lower elevations where foot/ski penetration to ground is a real possibility.

Problems

Wind Slabs

Alpine areas have been ravaged by the wind, so wind slabs are everywhere. Not only do they make for bad skiing, but in certain features they feel quite triggerable.

Avoid travelling in areas that have been reverse loaded by winds.Caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

With the first warm day in a while, watch for solar triggered sluffing from steep sunny slopes. These may or may not be an issue in themselves, but could trigger a slab on the slopes below.

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

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 1.5

Deep Persistent Slabs

This problem is a "low probability, high consequence" situation. While difficult to trigger, if the layer does fail it will result in a full depth avalanche.

Be aware of the potential for wide propagations due to the presence of hard windslabs.Be aware of the potential for full depth avalanches due to deeply buried weak layers.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1.5 - 3

Valid until: Feb 27th, 2019 2:00PM