Avalanche forecast

Kootenay Boundary

Apr 1 – 2, 2013Avalanche Canada
View on map
Archived · expired 14 years ago

Avalanche danger

Wed
Thu
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
Open full map

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
    With solar radiation and warm daytime temperatures, cornices may become unstable. There is a chance the weight of a cornice dropping onto the slope below could trigger an avalanche on the Mid-March crust.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–4
    Solar aspects are likely to see loose wet avalanches when the sun comes out and temperatures start to warm. Wet slab avalanches are also possible, particularly on solar aspects where a crust or smooth ground cover exists.

Snowpack Summary

Large cornices loom over many slopes. The upper 10 cm of surface snow has become moist and wet up to 2300 m, and melt-freeze conditions exist. Surface facetting and surface hoar (up to 12 mm) are prevalent on Northerly aspects.The surface snow overlies an old crust (down 50-60 cm) which exists up to ridge top. The bonds with the crust have gained strength in most places, and most test results are showing resistant planar fracture characteristics. Snowpack variability exists; it is important to dig down and test weak layers before diving into your line.

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 3.0 and freezing levels riding to 2400 m. Ridgetop winds will blow light from the West.Wednesday/Thursday: Mainly cloudy with light precipitation amounts. Alpine temperatures around zero degrees and freezing levels around 2100 m. Ridgetop winds light from the West.

Avalanche Summary

Glide cracks are opening up and releasing, use extra caution or just straight up avoid them. On Sunday a size 3.5 glide crack release occurred from a West aspect at 2300 m and ran to the valley bottom. Loose wet avalanches up to size 2 continue to be widespread. Avalanche control work using explosives triggered loose snow and slab avalanches up to size 2.5 on SE-SW aspects. 

Regions covered