Avalanche forecast

Jasper

Apr 20 – 21, 2019Parks Canada
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Archived · expired 7 years ago

Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Up to 30cm of recent heavy snow with winds has activated the problems with continuing natural activity. Give the new snow a couple of days to settle and bond.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Up to 30cm of new heavy snow has built reactive slabs. They vary in depth from 20cm to up 60cm thick depending on loading patterns.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–3

    The new snow load initiated a natural cycle on this problem the past couple of days. Give it a few days to settle. Consequences would be severe if initiated.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2.5

    Activity increases with afternoon warming and less of an overnight freeze. Caution around terrain traps where small slides would have severe consequences.

Weather Forecast

The next couple of days will be generally sun and cloud, no new snow except for maybe a little on Monday and Tuesday, and rising incrementally freezing levels. A wind event may arrive Monday evening with 70km/hr winds.

Snowpack Summary

Moderate winds, mild temperatures and 30cm of new heavy snow Thursday night created widespread slabs in the alpine and into tree line. It rained at lower elevations making isothermal conditions where enough snow exists. A persistent facet weak layer down 40-70cm exists in some locations.

Avalanche Summary

Saturday's field patrol observed loose wet up to size 2, persistent slabs to size 3 on mainly NE aspects in alpine, and also thin windslabs size 2-2.5 E aspects. Yesterday there was a natural cycle with the recent 30cm storm. Friday's avalanche control on Highway 93 produced several wind slab avalanches up to size 2 and some stepped down.

Confidence

Regions covered