Avalanche forecast

South Rockies

Apr 1 – 2, 2013Avalanche Canada
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Avalanche danger

Wed
Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Danger could INCREASE TO CONSIDERABLE with intense radiation on south and west aspects, especially at treeline and below. Be aware of how the warm weather is changing the snowpack.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–5
    Large looming cornices exist on most ridgelines. They are a hazard in themselves and they could trigger slopes below.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–4
    Warmer temperatures and sunshine promotes deterioration within the upper snowpack. If surface snow becomes moist or wet, loose wet avalanches are likely. Watch solar aspects.

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–6
    Large wet slab, and glide crack releases have been widespread on South-West aspects.

Confidence

Good - Timing or intensity of solar radiation is uncertain

Weather Forecast

The weather pattern starts to change as the dominating upper ridge weakens allowing a more onshore flow, bringing cloudy skies and light precipitation.Tuesday: Mix of sun and clouds. Alpine temperatures near 2.0 and freezing levels riding to 2500 m. Ridgetop winds will blow light from the West.Wednesday/Thursday: Mainly cloudy with light precipitation amounts. Alpine temperatures near 2.0 and freezing levels around 2200 m. Ridgetop winds light from the West.

Avalanche Summary

On Monday, numerous wet slab avalanches and glide crack releases were reported up to size 3 from South-West aspects.

Snowpack Summary

We are in a classic spring melt-freeze cycle. The surface snow becomes moist  up to 2200m on all aspect and to ridgecrest on south and west facing slopes. Large cornices looming cornices threaten many slopes below. Surface hoar growth and surface facetting is happening at night on high sheltered, northerly aspects. A buried rain crust can be found down 50 cm and exists up to around 2100 m. The bonds at the crust has shown variability though the region. It is important to dig down and test weak layers before dropping into your line. A large trigger such as a cornice fall or a skier/sledder hitting the sweet spot, could potentially trigger a large avalanche on this layer.

Regions covered