Bulletin d’avalanche

Jasper

Apr 23, 2018Parks Canada
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Archivé · expiré 8 years ago

Danger d’avalanche

Tue
Wed
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

Solar triggered avalanches and cornice failures are likely to increase in frequency the next few days as each day will be warmer than the previous days.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2.5
    SW winds Saturday have added to the existing wind slab and cornice problem. Although mostly thin, some wind slabs are up to 40cm thick in alpine terrain. Once initiated the potential to trigger deeper weaknesses exists resulting in larger avalanches.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    Triggering this slab have been most reactive to large triggers such as a cornice failures.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    Pay close attention to the effect of solar radiation and daytime warming. Point release from rocks and cliff terrain can trigger isothermal snow below. This will be of most concern in the late afternoon.

Weather Forecast

Monday will be sun and cloud, no new snow, high of 0 C, light SW winds, and 2300m freezing level. Tuesday will be similar, but with 2500m freezing level. Wednesday will be similar but much warmer with 3500m freezing level. 

Snowpack Summary

Windslabs are up to 40cm deep. Sun or temperature crusts extend to treeline and continued into the alpine on southerly slopes. Persistent slabs can be found on most aspects at treeline and above. These have been most reactive to large triggers like cornice failures. Below 1,900m the snowpack is going isothermal on a daily basis.

Avalanche Summary

Sunday there  was a report of a size 2 slab avalanche on the NE slopes of Lectern, initiating in the alpine and running in to treeline. Also a couple of size 2-3 moist loose avalanches observed in the Icefield's area starting in steep solar affected alpine gullies and running far.

Confidence

Timing or intensity of solar radiation is uncertain on Monday

Régions couvertes