Bulletin d’avalanche

Jasper

Avalanche Canada
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Danger d’avalanche

Wed
Thu
Alpin
2 · Modéré
Limite forestière
Conditions printanières
Sous la limite
Conditions printanières
Périmé — ce bulletin a expiré 4 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Take a moment to read about spring conditions ratings. Cool weather over the next few days will improve stability as snow surfaces re-freeze.

Fragile cornices are heavy and may collapse without warning, triggering subsequent slab avalanches. Avoid travel below cornices.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–3

    Cornices are large and fragile right now. Recent cornice failures have also been large enough to trigger slabs below. Keep an eye on your overhead hazards.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–3

    A persistent weak layer of facets is down 80–120 cm and may still be triggerable by humans in shallow areas, and by large loads like collapsing cornices or wet loose avalanches. This problem exists on all aspects, but has been most active on solar slopes.

  • Loose Wet

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

    Temperatures are trending cooler this week, but the sun remains powerful when it does break through. Pay close attention to the snow surface - avoid slopes that are becoming wet.

Confidence

Avalanche Summary

Cornices are ripe and fragile. On Monday, our field team observed a new cornice failure near Snowdome. Saturday's patrol along the Icefields and the Maligne range noted cornice failures of which some are triggering slabs on the slopes below.

A size 3 persistent slab was also observed this Friday on Sunwapta peak, occurring in the alpine and treeline on a West aspect.

Snowpack Summary

A freeze-thaw cycle has occurred at all elevations on solar aspects. Dry or wind-affected surfaces persist on high north-facing alpine terrain. Below 2300m, multiple melt-freeze crusts are layered in the snowpack.

The January 24th layer is buried 80–120 cm deep and remains a lingering concern in the alpine. The lower snowpack is generally well consolidated in deeper areas, while shallow areas remain weaker and more faceted.

Weather Summary

Tuesday

Cloudy skies and flurries starting Monday night will deposit up to 13cm in alpine areas. Freezing levels will descend to 1700m. Alpine high -4°C. Southwest winds will be 20km/h with gusts up to 50km/h.

Wednesday

Freezing levels continue to descend to valley bottom. Expect an overnight low of -11°C with alpine temperatures reaching a high of -5°C. West winds will be light with gusts to 45km/h. Potential for convective weather.

Thursday

A mix of sun and cloud with isolated flurries adding a trace of new snow. Low -13°C and warming to -5°C. Freezing level at valley bottom. Light Northwest wind.

Terrain and Travel Advice

  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.

Régions couvertes