Bulletin d’avalanche

Waterton Lakes

Feb 17 – 20, 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

Fast travel and good weather make for some of the best conditions in weeks. The snowpack has gained a lot of strength but problems continue to linger in the high and shaded terrain where deep layers are not protected by thick crusts.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–2
    Although these old slabs have seen a lot of abuse from warm temperatures they do produce the only shears in the upper snowpack. Keep an eye on these if you are considering taking on serious terrain.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–2
    Given the amount of sun in the forecast and that cornices exist above some of the more sensitive snowpack areas out there right now, keep your mind tuned to your exposure. These big triggers may get the deep persistent slabs moving.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3
    Now 40 to 120cm 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

After a cold start to the day on Monday clearing skies and light winds will allow modest heating under a gradual warming trend. By Wednesday freezing levels could reach the alpine especially combined with clear skies however winds may start to increase as well. More cloud is expected by Thursday. Solar heating seems like the variable to watch.

Snowpack Summary

10cm of snow that fell over the weekend sits on rain and temperature crusts to 2000m and thin solar crusts to mountain top. Below this old windslabs cap the 50 to 80 cm slab that seems well bonded to the Jan 31 crust. The Mid-December layer down about 1m average is still a concern in high shaded terrain where there are no strong crusts above it.

Avalanche Summary

There was significant solar and heat induced loose moist activity while conditions remained warm last week. Things have cooled over the weekend and the snowpack has begun to refreeze creating strong surface crusts below tree line. Avalanche activity has diminished as a result with no new avalanches seen since Saturday.

Confidence

Freezing levels are uncertain on Wednesday

Régions couvertes