Bollettino valanghe

North Rockies

Dec 17 – 18, 2023Avalanche Canada
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Archiviato · scaduto 3 years ago

Pericolo valanghe

Tue
Wed
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato

In sintesi

Be patient, choose mellow terrain, and give the snowpack time to adjust to the new load.

Storm slabs and buried weak layers may be primed for human triggering.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    Buried surface hoar remains concerningly reactive in snowpack tests. It is difficult to define the specific terrain where you could trigger this layer, due to a lack of snowpack and avalanche observations.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1.5–2.5

    Recent snow and wind formed reactive slabs at all elevations. Use extra caution around ridgecrests, rolls, and on convex slopes. Retreat to mellower terrain if you find signs of instability like shooting cracks, or recent avalanches.

Confidence

Moderate

Avalanche Summary

No new avalanches were reported on Saturday before 4 pm. We expect that human triggered avalanches will remain likely on Sunday.

If you go out in the backcountry, please consider sharing your observations on the Mountain Information Network (MIN).

Snowpack Summary

Friday night, 20-30 cm of storm snow arrived with strong southwest winds forming reactive storm slabs. This recent snow sits on old, hard surfaces, like windslabs or a frozen crust, which are good sliding surfaces for avalanches.

A concerning layer of surface hoar can be found 50-90 cm below the snow surface.

A crust with sugary facets beneath it can be found just above the ground. Average snowpack depths at treeline range from 65 to 100 cm.

Weather Summary

Saturday Night

Partly cloudy. Trace of snow expected. Light to moderate southwest ridgetop wind. Treeline low around -6°C. Freezing level at valley bottom.

Sunday

Partly cloudy. No new snow expected. Moderate southwest ridgetop wind. Treeline high around -2°C with possible temperature inversion.

Monday

Cloudy. 5-10 cm of snow expected. Light southeast ridgetop wind. Treeline temperature around -2°C with possible temperature inversion.

Tuesday

Cloudy. 2-5 cm of snow expected. Light to moderate southwest ridgetop wind. Treeline temperature around -2°C with possible temperature inversion.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
  • Give the new snow several days to settle and stabilize before pushing into bigger terrain.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Regioni coperte