Avalanche forecast

South Columbia

Apr 7 – 8, 2013Avalanche Canada
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Avalanche danger

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

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–5
    Wind slabs are likely growing old and tired but they may still be a problem on high elevation lee slopes.  The large cornices that loom over many slopes may fail with daytime heating/solar input.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–4
    Conditions at and below treeline change radically with air temperature and solar input this time of year.  Daytime heating and direct sun will likely be followed by another round of loose snow avalanches.

Confidence

Fair - Intensity of incoming weather is uncertain on Wednesday

Weather Forecast

Synopsis: A ridge builds into the region Monday followed by a moderate system Tuesday night. A strong zonal flow sets up in the wake of the Tuesday night storm.Monday: Freezing Level: 1500m. Precip: Nil Wind: Light, NW.Tuesday: Freezing Level: 1800m Precip: 10/20mm – 10/30cm (overnight) Wind: Mod, SWWednesday: Freezing Level: 1900m Precip: Convective flurries. Wind: Strong, SW.

Avalanche Summary

Natural storm slab avalanches to size 2.5 were reported from upper elevations on Saturday.  Down below 2000m there were several loose moist avalanches triggered by riders to size 1.5.  Glide releases to size 2.5 continue to be reported on all aspects.

Snowpack Summary

It's still winter up above 2000m.  At the upper elevations 15-30cm of new snow is covering a crust or moist snow. In some places in the alpine and at treeline this new snow may have buried a recently formed layer of surface hoar or facets. At lower elevations (below 2000m) rain has made the snow surface wet or moist down 50-100cm. New snow combined with wind will has made large cornices even bigger.The March 10th surface hoar/crust interface is buried more than 100cm in most places. Although unlikely to trigger, this deep persistent weakness remains a concern because of the potential for very large avalanches particularly with heavy triggers such as cornice falls or lighter triggers on solar aspects where the crust is more prevalent. Below this the snowpack is strong and well settled.

Regions covered