Bulletin d’avalanche

Long Range Mountains

Apr 8 – 9, 2023Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

Mon
Tue
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
Sans niveau

Points saillants

Heightened avalanche conditions exist on leeward slopes where new and recent snow has been wind-loaded into reactive slabs.

We will likely see an increase in avalanche danger in the following days with warming temperatures and sun.

Problèmes avalancheux

  • Wind Slabs

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

    Small amounts of new snow and wind are forming fresh wind slabs in leeward terrain features. They may be especially reactive where they sit over a crust at lower elevations.

    In the alpine, older wind slabs may be more stubborn to trigger but given their density and thickness, could potentially have high consequences.

  • Loose Wet

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

    After the weekend, as temperatures warm and skies clear, loose wet avalanches will become increasingly likely. Recent soft snow will be especially sensitive upon first exposure to positive temperatures or strong sun. Watch for signs of warming like moist or wet snow, pinwheeling and point releases.

Avalanche Summary

Wind slabs and cornices were reactive prior to the weekend. Natural and human-triggered wind slabs size 1-2 were reported in the White Hills and Big Level areas. Wind slabs were predominantly on east aspects in the alpine. Natural cornice falls were observed in the Tablelands.

Confidence

Moderate

Snowpack Summary

Small amounts of new snow continue to accumulate. Around 10 cm of recent snow sits over wind-hardened surfaces in the alpine and crust at lower elevations.

Snow from earlier in the week appears to be well-bonded to an underlying rain crust but contains a few storm interfaces 20-40 cm deep that remain reactive in snowpack tests. This may include a layer of graupel which could be slow to bond.

The remainder of the snowpack is composed of alternating layers of crusts and wind-hardened snow, effectively bridging any deeper weak layers.

Weather Summary

Saturday night

A trace of new snow. Moderate northwest wind. Alpine low -12 C.

Sunday

Flurries intensifying in the afternoon, accumulating around 5 cm. Moderate westerly wind. Alpine high -8 C.

Monday

5-10 cm overnight then clearing to mostly sunny. Moderate northwest wind. Alpine high -2 C. Freezing level rising to 500 m.

Tuesday

Mostly cloudy. Moderate southwest wind. Alpine high +3 C. Freezing level rising to 1500m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be especially cautious as you transition into wind affected terrain.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.

Régions couvertes