Bulletin d’avalanche

Northwest Coastal

Apr 19 – 20, 2019Avalanche Canada
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Archivé · expiré 7 years ago

Danger d’avalanche

Sun
Mon
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

Stronger sunshine and warmer temperatures are the concern for Saturday. New snow that sees sun for the first time is expected to shed easily, whether naturally or with light triggers. Please post your observations to the Mountain Information Network!

Problèmes avalancheux

  • Wind Slabs

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

    Strong winds likely packed much of our recent snow into wind slabs focused on lee (north to east) slopes. This problem increases with elevation and proximity to the coast. Slabs that formed over crust at the previous surface may be touchy.

  • Loose Wet

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

    Sunshine is in the forecast for the first time after a several days of steady snowfall. Expect recent snow to shed easily from steep slopes that see direct sun. This may occur naturally or with a human trigger.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Friday night: Clear with cloudy periods. Light to moderate northwest winds.

Saturday: A mix of sun and cloud. Light variable winds. Alpine high temperatures around -2 with freezing levels to 1200 metres.

Sunday: Cloudy with scattered flurries bringing approximately 5 cm of new snow, increasing overnight. Moderate south winds increasing overnight. Alpine high temperatures around -1 with freezing levels to 1300 metres.

Monday: Cloudy with continuing flurries bringing 10-20 cm of new snow and new snow totals to 20-35 cm. Moderate rain below about 1200 metres. Precipitations easing overnight. Strong south winds, easing over the day. Alpine high temperatures around 0 with freezing levels to 1500 metres.

Avalanche Summary

No new avalanches have been reported in the region. Please submit your observations to the Mountain Information Network.

Snowpack Summary

5-10 cm of new snow fell over Thursday night, bringing new snow totals since Tuesday to approximately 20-40 cm. Moderate to strong southwest winds are expected to have formed reactive wind slabs with the new snow over the same time period.

The new snow has buried another wind-redistributed 5 to 20 cm of snow that fell on Saturday. This previous snow remains dry on high elevation north facing slopes, while a 5 to 10 cm melt freeze crust can be found instead on all other aspects.

The April 4th crust is now down 30 to 100 cm on high elevation north facing slopes. Surface hoar and facets were previously observed on this crust and it recently produced sudden results in snowpack tests. It is uncertain whether it became involved in any natural avalanche activity during the past few stormy days.

At lower elevations, ongoing warm weather has been promoting isothermal snowpack conditions and melting the snowpack away.

Régions couvertes