Bulletin d’avalanche

Northwest Inland

Apr 11 – 12, 2016Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

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

A brief return to winter in the alpine on Tuesday. New snowfall and strong southerly winds are expected to form thin new wind slabs at higher elevations.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    New snowfall and strong southerly winds may form thin new wind slabs on Tuesday. These slabs will overlie a firm melt-freeze crust which may increase the slab reactivity and likelihood of triggering.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–5
    The timing of failures is unpredictable. Unsupported sections are extra suspicious. Dropping chunks are a hazard in themselves and they may also trigger a slab avalanche on the slopes below. Watch and limit your exposure to overhead hazards.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    Loose wet sluffing is possible on steep slopes during periods of rain. Wet slabs are also possible, especially at lower elevations.

Weather Forecast

A weak storm system is expected to reach the coast Monday overnight.  2-5cm of snowfall is forecast for Tuesday.  Strong southerly winds are expected in the alpine with afternoon freezing levels around 1300m.  Light snowfall may continue Tuesday overnight and should be done by Wednesday morning.  A mix of sun and cloud is forecast for Wednesday and Thursday with light alpine winds and afternoon freezing levels around 1400-1500m. 

Avalanche Summary

On Sunday afternoon, loose wet avalanches up to size 2.5 were reported in the far north of the region.  With the arrival of spring, field observations and data have become very limited in the region. A lack of avalanche reports does not mean avalanches are not occurring.  On Tuesday, thin new wind slabs may form in the alpine. Cornices have been weak recently and may fail naturally with storm loading. Loose wet avalanches are possible at lower elevations that see rainfall.

Snowpack Summary

Melt-freeze conditions are expected to be widespread except possibly on high elevation north aspects. Surface crusts are forming overnight and breaking down during the day. The snowpack's strength is directly related to the thickness and strength of these crusts. Where there are layers in the snowpack, they are generally bonding. A widespread crust/facet layer from early February and depth hoar at the bottom of the snowpack (primarily in northerly & inland areas) are dormant. Strong, thick crusts in the upper parts of the snowpack have limited the reactivity of these old layers; however, they could potentially once again produce isolated yet large avalanches with prolonged periods of warming.

Régions couvertes