Bulletin d’avalanche

Jasper

Dec 29 – 30, 2012Parks Canada
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Archivé · expiré 14 years ago

Danger d’avalanche

Sat
Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Continued loose snow avalanches on steep alpine and tree line slopes.  Be prepared for these sloughing on or under slopes and  ice climbs .

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–3
    Moderate to strong westerly winds have created wind slab conditions on slopes and along ridge lines especially in the Icefields area. No avalanche activity has been observed on this condition, however, we have not tested the bonding strength.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    On Wednesday, small natural slab avalanches to size 1.5 were observed on the basal facets in thin snowpack areas. Triggering is most likely to happen along edges of shallow pockets and from thin spots like rocks or trees.

Weather Forecast

Light NW winds with the possibility of some light snow flurries can be expected on Saturday.  Cool overnight temperatures will warm to above seasonal values by the afternoon with sunny breaks.

Snowpack Summary

Moderate to strong SW winds have created slab conditions on open tree line slopes and along ridge lines in the alpine.  The mid-pack is facetting but remains strong where it is deeper than a meter.  In shallow areas, facetting has weakened it significantly.

Avalanche Summary

In the past 2 days, surface facets have created numerous small loose avalanches at tree line and above in the Icefields area.  These slides have little mass and have not as yet triggered the wind slabs beneath them.  No natural slab avalanches were observed today.

Confidence

Due to the number and quality of field observations on Saturday

Régions couvertes