Bulletin d’avalanche

North Rockies

Mar 12 – 13, 2024Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

Thu
Fri
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré

Points saillants

Natural avalanche activity could spike on slopes facing the sun.

Rider and remote triggering of large avalanches are an ongoing concern. Choose conservative, low consequence terrain.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2

    Ongoing snowfall and southerly wind have formed wind slab on northerly aspects and cross loaded others.

    These avalanches have the potential to step down to deeper layers if triggered.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–2.5

    A weak layer of facets rests above a hard-melt freeze crust that formed early February. This layer remains in the depth for human triggering.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–1.5

    Even short periods of sunshine can initiate natural avalanche actively. Especially from steep slopes facing the sun.

Confidence

Moderate

Avalanche Summary

No new avalanche reports by 4pm Tuesday.

Check out this great MIN describing conditions near Hasler.

A few size 1 and 1.5 rider triggered persistent slab avalanches have been reported in the last couple days as well as a few size 2 natural wind slabs. We expect wind and persistent slabs to be rider triggerable. Avoid solar slopes when the sun is out.

Snowpack Summary

New snow is being redistributed by ongoing southerly winds, leaving widespread wind-affected surfaces in exposed terrain. Numerous sun crusts exist on steep south facing slopes. The snow surface will likely become moist at low elevations.

A thick and hard widespread crust that formed in early February is buried about 50 to 110 cm deep. This crust has a layer of facets above it in many areas.

The eastern portion of this region is much shallower with a highly variable and wind-affected snowpack.

Weather Summary

Tuesday Night

Clear periods with isolated flurries. 10 to 20 km/h west ridgetop wind. Treeline temperature -10°C. Freezing levels valley bottom.

Wednesday

Mix of sun and cloud. 10 to 15 km/h southwest ridgetop wind. Treeline temperatures near -8°C. Freezing level rising to 1400 m.

Thursday

A mix of sun and cloud. 10 km/h northwest ridgetop wind. Treeline temperatures near -3°C. Freezing level rising to 1600 m.

Friday

Sunny. 15 km/h northwest ridgetop wind. Treeline temperatures near 0°C. Freezing level rising to 2500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Choose conservative terrain and watch for clues of instability.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Régions couvertes