Avalanche Forecast

Issued: Apr 27th, 2017 3:13PM

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

mike.koppang, Alberta Parks

Kananaskis.

Recent snow over this past week should keep avalanche conditions in the forefront of your mind. Good skiing can be found on north aspects.

Summary

Confidence

Weather Forecast

Overnight on thursday we may see up to an additional 15cm of snow and another 5-10cm on Friday. Winds are forecast to be light with freezing levels are 2000m. Start early while there is still a good freeze and be home early.

Avalanche Summary

A few recent sz 3 avalanches have been observed failing to ground initiating in Alpine terrain on N through E aspects. Cornices are large, and are the suspected trigger in these avalanches. There has also been loose wet at lower elevaitons, and loose dry in Alpine terrain from steep unskiable features.

Snowpack Summary

20-30cm of snow has fallen over the past few days (23-27th of April) with warm temperatures and generally light winds. This new snow is settling rapidly at lower elevations and more slowly in alpine areas. Expect to encounter a series of melt freeze crusts on solar aspects up the 3100m and dry powder snow in alpine terrain on northern aspects. At 2200m and below, expect to encounter widespread surface crusts that will be supportive in the morning and less so in the afternoon. On solar aspects, watch for the new snow forming thin slabs or loose dry slides on the underlying crusts that react quickly to a skiers weight.

Problems

Cornices

Cornices are collapsing with the warmer temperatures triggering slabs on underlying slopes.

Stay well back from cornices.Extra caution needed around cornices with current conditions.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

2 - 3

Deep Persistent Slabs

In general the bottom layers are still weak and suspect. Especially in the alpine and/or polar aspects. Large triggers such as a big influx of heat or a cornice collapse can wake up these basal layers.

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Travel early before the heat of the day, and avoid big slopes in the afternoon.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Loose Wet

As the snowpack warms we become increasingly susceptible to loose wet avalanches. Steep terrain and gullies should be treated with caution if the snow is moist or wet.

If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.Use extra caution on slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 28th, 2017 2:00PM