Bulletin d’avalanche

Jasper

Apr 17 – 18, 2025Avalanche Canada
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Archivé · expiré last year

Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
Sans niveau

Points saillants

Start and end your day early. Friday will get very warm in the afternoon and evening, which will increase the avalanche hazard.

The deep persistent layers are still in the snowpack. Be careful on high north aspects where there are no crusts above these layers.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Isolated wind slabs have been building from south-west winds and now the winds have switched to a more northerly direction, look out for loading in not the usual places.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2

    High freezing levels on Friday will see wet loose avalanches at all aspects and elevations. These have the potential to step down to deeper layers. Start your day early and pay attention to the overnight refreeze

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–4

    This is combination of our midseason persistent weak layers and the weak facets & depth hoar that live at the bottom of the snowpack. The likelihood of triggering this layer has been decreasing but if triggered, would likely result in a large destructive avalanche.

Confidence

Moderate

Avalanche Summary

Recently large cornice failures and small wind slabs have been observed at alpine elevations.

On Sunday a size 3.5 deep persistent avalanche was observed on the subpeak to the east of Mt. Saskatchewan.

Snowpack Summary

5-20 cm of recent new snow exists in sheltered areas. Wind slabs exist on all aspects in the alpine due to recent variable wind loading. The upper snowpack at tree line & below is a series of melt-freeze crusts and moist snow. The mid-pack and lower snowpack is dry, faceted and weak. High north aspects do not have any of crusts in the upper snowpack which may make it easier to trigger the deep persistent layer.

Weather Summary

Thursday Night

Clear with cloudy periods.

Precipitation: Nil.

Alpine temperature: Low -3 °C.

Ridge wind light to 25 km/h.

Freezing level at valley bottom.

Friday

A mix of sun and cloud with isolated flurries.

Precipitation: Trace.

Alpine temperature: High +2 °C.

+14 in Jasper townsite

Ridge wind west: 15 km/h.

Freezing level: 2500 metres.

Saturday

Mainly cloudy with scattered flurries.

Accumulation: 4 cm.

Alpine temperature: Low -4 °C, High 0 °C.

Ridge wind west: 15-30 km/h.

Freezing level: 2200 metres.

Terrain and Travel Advice

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.

Régions couvertes