Bulletin d’avalanche

Kootenay Boundary

Mar 18 – 19, 2018Avalanche Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

Tue
Wed
Alpin
1 · Faible
Limite forestière
1 · Faible
Sous la limite
1 · Faible
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Points saillants

Low danger does not mean no danger. Stubborn old wind slabs, large cornices and the daily cycle of loose wet avalanches demand our respect.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–1.5
    Be aware that stubborn old wind slabs may be sensitive to human triggering near ridge crest. Loose wet avalanche danger increases with daytime warming at lower elevations and on south aspects.

Confidence

High -

Weather Forecast

Monday and Tuesday offer a drying trend for most of the province. A low approaching from the Gulf of Alaska may bring precipitation to the region beginning Wednesday night.MONDAY: Scattered cloud cover, freezing level beginning at 700 m rising to 1600 m, light to moderate west/northwest wind, trace of precipitation possible. TUESDAY: Broken cloud cover, freezing level beginning at 500 m rising to 1500 m, light to moderate southwest wind, no significant precipitation expected. WEDNESDAY: Scattered cloud cover, freezing level beginning at 500 m rising to 1700 m, light to moderate south/southwest wind, a few mm of precipitation possible Wednesday night.

Avalanche Summary

No new avalanche activity to report from Saturday.Avalanche activity on Friday was limited to snowballing on solar aspects.On Thursday small loose avalanches were reported on steep features as the new snow ran on a crust. A few small skier triggered wind slabs were also reported from east facing alpine terrain.

Snowpack Summary

A crust has formed on all solar aspects. Fresh surface hoar has begun to form on polar aspects (those that face north and east) near ridgetop.About 5 cm of snow is between the surface and another interface that mirrors the surface; crust on solar, surface hoar on high elevation north.Snow that fell March 8th/9th was redistributed by west/southwest wind, forming wind slabs at high elevations. These wind slabs rest on a layer of surface surface hoar about 25 to 40 cm below the surface which has not been recently reactive.A mix of weak layers exist 50 to 100 cm below the surface, including small surface hoar on shady aspects and a crust on solar aspects. These layers are expected to have gained strength from recent cycles of warming and cooling. Like other deeper weak layers that formed in January and December, they are considered dormant at this time. These deeper layers include several surface hoar and facet layers 1 to 2 m below the surface and a crust/ facet interface near the base of the snowpack.

Régions couvertes