Bulletin d’avalanche

South Rockies

Jan 12, 2019Avalanche Canada
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Archivé · expiré 8 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

A big rise in freezing levels may mean that the deep persistent slab wakes up. A lot of uncertainty exists as to what this layer will do as temperatures climb. High levels of uncertainty are best managed by choosing conservative terrain.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2
    Slabs may become more reactive as temperatures rise and the sun comes out.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3
    Deeply buried weak layers remain a concern, especially as temperatures rise and the sun comes out. Large loads like cornices may trigger this layer as well, and cornice failures become more likely during warm, sunny conditions.

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

Exact freezing levels and alpine temperatures are difficult to forecast in the coming days with mild temperatures and temperature inversions dominating the weather pattern this weekend.FRIDAY NIGHT - Cloudy with clear periods / southwest winds, 10-30 km/h / alpine low temperature near 0 / alpine temperature inversionSATURDAY - Cloudy with sunny periods / southwest winds, 10-30 km/h / alpine high temperature near +5 / Freezing level 1800 m / strong alpine temperature inversion with above freezing temperatures possible to 3000 mSUNDAY - Sunny with cloudy periods / southwest winds, 10-30 km/h / alpine high temperature near +7 / freezing level 3300 m MONDAY - Sunny / southwest winds, 20-40 km/h / alpine high temperature near +5 / freezing level 3000 m

Avalanche Summary

One size 2-2.5 natural avalanche was reported on a north aspect at 2200 m on Friday. This avalanche was likely triggered by a rock fall, and ran on the deep persistent layer at the base of the snowpack.A few size 1 natural and explosives triggered avalanches were reported in the region on Thursday.

Snowpack Summary

10-20 cm of recent storm snow has been redistributed by strong winds and has formed wind slabs at upper elevations. This new snow sits on previous hard wind slabs, a scoured and shallow snowpack on exposed ridges, and soft snow in sheltered areas. Large variability in snow depths still exists in the region, ranging from almost no snow to nearly 200 cm in some areas. For average snowpack areas, expect to find weak and sugary faceted snow around 50 to 100 cm deep, which extend to the ground. This weak bottom half of the snowpack has been the culprit for large avalanches in the region over the past few weeks. Warming temperatures and sunshine over the coming days could re-activate this layer, resulting in a possible avalanche cycle.

Régions couvertes