Avalanche forecast

Cariboos

Apr 18 – 19, 2013Avalanche Canada
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Archived · expired 13 years ago

Avalanche danger

Sat
Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    New snow and moderate winds will likely build new wind slabs on lee slopes. Buried wind slabs exist on a variety of aspects at treeline and above. Large, looming cornices exist on ridgelines and pose a threat to slopes below.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–6
    A weak interface is buried about a metre down. A surface avalanche stepping down, cornice fall, or the weight of a person from a thin-spot trigger point could trigger a large and destructive avalanche.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Initially, the approaching frontal system will spread light-moderate precipitation amounts with rising freezing levels. Towards the end of the forecast period a cooling, drying trend will take place before a big warm-up next week.Friday: Overcast with light- moderate precipitation amounts. Ridgetop winds will blow moderate from the SW and freezing levels will rise to 1900 m.Saturday: Overcast with moderate precipitation amounts. Ridgetop winds will blow moderate from the NW and freezing levels near 1400 m then falling to valley bottom overnight.Sunday: Mostly sunny skies with a cooling, drying trend. Freezing levels will rise to 1200 m by the afternoon.

Avalanche Summary

On Wednesday, a remotely triggered  a size 2.5 slab avalanche from a North aspect at 2700 m occurred from the ridgetop. A large whumph was heard and felt with no involvements.

Snowpack Summary

Over the past 2 days, melt-freeze crusts have formed on solar aspects. North aspects remain dry, with new surface hoar development and surface faceting. Forecast snow and wind may build new wind slabs, burying older wind slab problems found at treeline and above. Cornices are very large and remain a concern.In some locations a surface hoar interface exists buried within the upper metre of the snowpack. This is mostly found on northerly aspects at upper elevations.  It may be slowly gaining some strength, but I’d remain suspicious and practice caution around these slopes. On other aspects, the storm snow overlies a crust. This crust interface has recently become reactive in regions further south and may become reactive in your area with additional load.

Regions covered