Bulletin d’avalanche

Waterton Lakes

Feb 24 – 27, 2015Parks Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Tue
Wed
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible
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Points saillants

Watch out for fresh windslabs and be selective with your aspects to avoid solar crusts. Stability should improve with the expected cooling into the weekend.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2
    Fresh slabs can be found near ridgecrests at Treeline and in any lee features in the Alpine. Expect these to be sensitive to skier triggering especially while the temperatures remain warm Tuesday.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Watch for the sun to rapidly warm the surface snow and cornices, raising the hazard Tuesday morning with lingering warm air at upper elevations and a weak freeze expected. This activity will become unlikely beyond Tuesday afternoon with cooling.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3
    Now 50 to 150cm deep these slabs continue to stand out as a concern in the TL and ALP areas where there is not a strong Jan 31 crust over them (2200m+). Be particularly mindful in thin snowpack areas where this layer is more likely to be triggered.

Weather Forecast

More cloud development as a cold front pushes down from the NW should start to cool things by midday Tuesday and NW winds will continue.  As the front passes midday Wednesday expect  up to 5cm of snow followed by the winds shifting to the West and abating. Cooling temperatures, lingering clouds and trace amounts of snow through Thursday and Friday.

Snowpack Summary

15cm fell on the weekend and NE and NW winds have redistributed this into windslabs on treeline ridgecrests and more widespread locations in the alpine. Surface crusts can be expected on steep SE through SW slopes. The Mid-December layer that is down over 1m in most deep areas remains a concern in high shaded terrain presenting a shallow snowpack.

Avalanche Summary

A few minor windslabs have been observed in the alpine that were likely triggered by continued wind loading. Pin-wheeling and minor loose wet avalanches occurred with heating yesterday and today on steep S and very steep E slopes and this activity may continue Tuesday morning with strong solar and an alpine temperature inversion possible.

Confidence

Régions couvertes