Bulletin d’avalanche

North Rockies

Mar 18 – 19, 2024Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

Wed
Thu
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré

Points saillants

Continue to choose mellow terrain, and avoid being under steep slopes especially during periods of sun.

Triggering large avalanches is still possible until a strong surface crust forms.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3.5

    A weak layer of facets rests above a hard-melt freeze crust that formed early February. Human triggering of this layer remains possible until a hard surface crust starts to form.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2.5

    As temperatures and freezing levels begin to decrease and lower, sensitivity to triggering is excepted to rapidly plummet.

Confidence

Moderate

Avalanche Summary

No new avalanches were reported on Sunday.

On Saturday, a widespread natural avalanche cycle up to size 2.5 continued, with some loose wet avalanches even being reported on north aspects.

On Friday, several natural persistent slab avalanches were observed, primarily on solar aspects, up to size 2.5.

As temperatures start to drop, we expect natural avalanche activity to be less common.

Snowpack Summary

Previously moist or wet snow surfaces have began to form into a melt freeze crust. It is expected that this cooling will begin to build a strong and robust surface that will suppress sensitivity of triggering avalanches.

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 has a much shallower, highly variable and wind-affected snowpack.

Weather Summary

Monday Night

Clear. No new precipitation. Freezing level 2000 m dropping to 1200 m. Treeline temperature around -1 °C.

Tuesday

Becoming cloudy. Light to moderate southeast ridgetop wind. Freezing level 1200 m. Treeline temperature around -1 °C.

Wednesday

Cloudy. Moderate northeast wind. Freezing level dropping to valley bottom. Treeline low around -10 °C.

Thursday

Mostly cloudy. Moderate northwest wind. Freezing level dropping to valley bottom. Treeline low around -10 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • In times of uncertainty conservative terrain choices are our best defense.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Régions couvertes