Avalanche forecast

Kananaskis

Apr 4 – 5, 2017Alberta Parks
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Still some deep weak layers to be concerned with. And the transition to Spring has slowly begun - avalanche hazard will increase with solar radiation and daytime heating. Keep an eye on localized conditions.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    Not much natural avalanche activity with these wind slabs yet, but human-triggering is more likely in convex and unsupported features. These slabs seem confined to the Alpine.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2
    The intense April sun is causing a rapid increase in loose wet avalanche activity on solar aspects as the each day progresses.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–4
    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.

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

Wednesday is expected to be mainly cloudy with no precipitation. Winds will be 30km/h from the SW at ridgetop with Alpine temperatures near -3 C. Freezing levels should reach 2200m. Thursday and Friday may be warmer yet and should see a bit of sun mixed with light flurries.

Avalanche Summary

One size 1.5 cornice failure occurred on Mt Buller in the past 24hrs, but the cornice did not trigger a slab on the underlying slopes. A few solar triggered loose wet avalanches up to size 2.0 were observed in steep Alpine and Treeline terrain today.

Snowpack Summary

A clear and cold night brought a good surface freeze to the snowpack overnight, but that changed quickly on steep solar aspects where snow was moist by late morning. Solar aspects have a variety of buried crusts, whereas polar aspects above 2100m have an average of 20cm of dry snow sitting on a variety of previous surfaces. Wind slabs are present everywhere in the Alpine except in sheltered features. Not much natural avalanche activity has occurred with these wind slabs, but many areas like ripe for human-triggering. As previously reported the mid-pack remains dense and strong, but the basal layers are very weak consisting of anywhere between 50 and 100cm of facets sitting on the ground. Forecasters still have low confidence for traveling in large Alpine terrain, unless there has been widespread previous avalanching.

Regions covered