Bulletin d’avalanche

South Coast

Mar 4 – 5, 2023Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

Mon
Tue
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué

Points saillants

Storm slabs remain a concern going into the weekend.

Make conservative terrain choices as you seek out great riding.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1.5–3

    This past week's snow is covering a crust facet combo layer. If triggered this weak layer could produce a large-scale avalanche.

    Here is a great video on this layer's development.

  • Storm Slabs

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

    Saturday may see another 20 to 25 cm fall on the already 70 to 130 cm of snow that has accumulated in the last seven days. Expect reactive storm slabs. In exposed areas expect to find that the wind has built even deeper deposits of snow that may contain slab properties.

    Storm slab reactivity is expected to persist for longer than is typical, particularly in areas where slabs are sitting on a weak layer of facets and/or a crust.

Confidence

Moderate

Avalanche Summary

Last weekend, a widespread natural cycle occurred throughout the region. Reports came in of very touchy human-triggered storm slabs (size 1 to 2) averaging 30 to 60 cm deep and up to 100 cm deep in wind-loaded areas.

Check out last Friday's North Shore Snowpack Update for a picture of the unusual snowpack setup leading into last weekend's storm.

Snowpack Summary

Saturday will see more snow falling and adding to the 90 to 120 cm that fell this past week. This snow was mostly dry and cold. Warming temperatures have increased the consolidation of the upper snowpack and may promote slab development.

This recent snow sits on a layer of concern made up of a crust with facets. It appears to be gaining strength, but this is a layer to watch out for.

The mid and lower snowpack is well-settled, strong, and consolidated.

Snowpack depths are reaching 250 cm at treeline.

Weather Summary

Friday Night

Cloudy, 15 to 25 cm accumulation, winds southwest switching to southeast 25 to 40 km/h, freezing level around 500 m.

Saturday

Mostly cloudy, 5 cm accumulation, winds southeast 35 to 40 km/h, freezing level climbing to 900 m.

Sunday

Cloudy with late day sunny breaks, 2 to 5 cm accumulation, winds southeast 15 to 30 km/h, freezing level to 900 m.

Monday

A mix of sun and cloud, trace accumulation, winds southeast 15 to 20 km/h, freezing level climbing to 1000 m by end of day.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
  • Keep your guard up at lower elevations. Storms slabs have been reactive at all elevations.
  • Loose avalanches may start small but they can grow and push you into dangerous terrain.
  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.

Régions couvertes