Bulletin d’avalanche

Kootenay Boundary

Mar 4, 2017Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Sat
Sun
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré

Points saillants

Strong SW wind and fresh snow Friday night may fuel another round of natural avalanches while most of us sleep. Light wind and lack of snowfall on Saturday may appear benign, but the mountains are currently primed for human triggered avalanches.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Ongoing snowfall coupled with strong SW wind is fueling a robust storm slab problem that is particularly problematic in wind exposed terrain, as a result the safest and conveniently best riding will be found in wind sheltered terrain below treeline.

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Saturday

Weather Forecast

A deep upper trough is moving through BC this weekend. The unsettled weather pattern should deliver continued precipitation and southwesterly winds to the mountains of the Kootenay Boundary through the forecast period. FRIDAY NIGHT: 5 to 20 cm of snow, strong to extreme southwest wind.SATURDAY: Overcast skies, freezing level beginning around 500m rising to 1000m in the afternoon, moderate SW wind, 5 to 10 cm of snow. SUNDAY: Overcast skies, freezing level beginning around valley bottom rising to 500m in the afternoon, light SW wind, 1 to 5 cm of snow. MONDAY: Overcast skies, freezing level beginning around valley bottom rising to 500m in the afternoon, moderate SW wind, 1 to 5 cm of snow.Visit avalanche.ca/weather for a more detailed mountain weather forecast.

Avalanche Summary

On Thursday control work produced storm slab avalanches to size 1.5 on NE, E and SE facing slopes. Reports from Wednesday include numerous natural, skier and explosive triggered storm/wind slab avalanches up to Size 2.

Snowpack Summary

30 to 80cm of snow has fallen in the last week, which is bonding poorly to a sun crust on previously sun-exposed slopes, or facets and large surface hoar on shaded aspects. Wind slabs have formed in exposed areas from winds out of the NW and now SW, with continued snow and wind forecast for Friday night and Saturday. A variety of crusts and thin surface hoar layers in the upper snowpack are becoming more of a concern with this increased load. Areas with a shallow snowpack (less than around 170 cm) generally have a weak snowpack structure with a deep persistent weakness of facets near the ground. There are a number of great MIN reports from Thursday and Friday here: https://avalanche.ca/mountain-information-network/submissions/

Régions couvertes