Bulletin d’avalanche

Northwest Coastal

Apr 19 – 20, 2016Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Thu
Fri
Alpin
Sans niveau
Limite forestière
Sans niveau
Sous la limite
Sans niveau
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Points saillants

Spring Conditions. Expect the likelihood of wet slab and loose wet avalanches to increase during the heat of the day. Watch for clues like snowballing that the surface is heating up and the snowpack may be losing strength.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Recent wind slabs should settle and bond overnight with overnight freezing levels dropping after a warm day. Some shaded north aspects may hold dry wind transported snow that may be easy to trigger.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–4
    Sunny skies and high freezing levels will weaken the surface snow on solar aspects. Shaded aspects in the alpine may warm up enough to release as loose wet avalanches.

  • Wet Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–5
    The likelihood of wet slab avalanches will increase with forecast high freezing levels and strong solar radiation. Areas that do not re-freeze overnight may become very weak early in the day.

Weather Forecast

Clear overnight with freezing down to at least 1000 metres. Moderate southerly winds on Wednesday with clear skies and freezing levels up to 2500 metres. Mostly clear on Thursday with moderate southeast winds and cloud developing in the late afternoon. Freezing level up to 3000 metres on Thursday. Cloudy and cooler on Friday with freezing levels around 2000 metres and moderate to strong southeast winds.

Avalanche Summary

Numerous wet slab avalanches up to size 3.0 were reported from near Stewart in the 1400-1600 metre elevation band. Most of these avalanches were triggered by explosives and they were about 50 cm deep.

Snowpack Summary

Clearing and cooling overnight has re-frozen the upper snowpack down to about 700 metres. Previously, there was 20-40 mm of precipitation in the past few days. Most of this has fallen as rain up to about 1800 metres. Most of the precipitation has been in the near coastal ranges, with Stewart and Kitimat receiving closer to 40mm and areas around Terrace closer to 20mm. Winds have been strong out of the south; reports from Stewart of gusts above 100 km/hr on Monday that have developed wind slabs in the high alpine. Rain has soaked the snowpack at lower elevations. Some recent crusts within the upper snowpack may continue to provide a sliding layer for loose wet avalanches when forecast temperatures and freezing levels spike in the next few days.

Régions couvertes