Bulletin d’avalanche

Jasper

Feb 17 – 18, 2018Parks Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Persistent midpack weaknesses are more pronounced in the northern portion of the forecast zone, with human triggering more likely than the Icefields area.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2.5
    Variable direction, strong upper elevation winds are continuing to create fresh windslabs and stiffen the snow surface well into Treeline locations.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2.5
    Whumpfing and cracking are signs of this layer's reactivity. Expect collapses to propagate larger distances with a wind-stiffened snow surface.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3.5
    Persistent slabs remain a problem. Areas exposed to large triggers such as cornices or smaller avalanches / sloughing from above are most likely to trigger this midpack weakness.

Weather Forecast

Flurries are expected overnight but with little accumulation resulting as a cold arctic front starts to sweep SW from the icy NE. Clearing expected Sunday and into next week with sunshine and cold nights.

Snowpack Summary

Available snow has been redistributed by strong, variable direction winds. In sheltered Treeline locations, the weak midpack layers are reactive down 50cm. Where snow remains in the Alpine, new wind slabs are reactive to triggering from additional load or solar, and wind-stiffened snow at Treeline is transmitting collapses large distances.

Avalanche Summary

Isolated windslab avalanches were observed today in the Icefields area and loose dry avalanches to size 2 were observed in the Tonquin valley. East, South, and North aspects have formed windslabs and large cornices that have failed in the last 48 hrs in the north portion of the forecast zone.

Confidence

Due to the number of field observations

Régions couvertes