Avalanche forecast

Jasper

Apr 4 – 5, 2017Parks Canada
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Archived · expired 9 years ago

Avalanche danger

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

Good skiing can be found in sheltered areas between 1900-2400m.Below tree line hazard will be low in the morning, but rising freezing level and solar heating will increase the hazard throughout the day.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3
    Cornice failure is hard to predict but is more likely with inputs like solar radiation and wind-loading.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Prolonged solar radiation and rising freezing levels with weaken the snowpack on South and West aspects, especially around steep and rocky areas.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–4
    This problem is unlikely to disappear. It can be triggered by large loads like cornice fall or windslab failure. Human triggering is most likely from shallow spots or on steep unsupported slopes.

Weather Forecast

Light flurries,  25-40km/hr SW winds with alpine high of -2 for Wednesday. Freezing levels rising to 2100m and forecasted to stay above 1800m until Friday. By the end of the week we might see up to 15cm of new snow at higher elevations.

Snowpack Summary

Good skiing between 1900-2400m in sheltered areas. Windslab along lee ridge-lines and cross-loaded gully features from SW winds. Mid-pack bridging basal weakness. Entire lower snowpack is weak with a combination of facets, Nov rain crust and depth hoar. Below tree line a supportive 20cm melt freeze crust sits above a weak facet layer to ground.

Avalanche Summary

No new avalanche observations on Tuesday. Previous cornice and windslab failures have triggered the deep persistent slab resulting large full path avalanches. Loose wet avalanches have previously occurred on steep south and west aspect below tree-line.

Confidence

Due to the quality of field observations on Tuesday

Regions covered