Avalanche forecast

South Coast Inland

Mar 18 – 19, 2017Avalanche Canada
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Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate

Highlights

A cooling trend will eventually help stabilize the snowpack. Continually reassess conditions as you travel into avalanche terrain and be aware of the potential for deeper weaknesses in the snowpack.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–4
    Heavy triggers such as a cornice fall or a small avalanche could potentially step down to weak layers buried about 1 m deep in the northern parts of the region.
  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Storm slabs may remain reactive at higher elevations and wind-affected terrain.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

SUNDAY: Clearing skies following the storm, light to moderate west winds, alpine temperatures drop to around -10 C.MONDAY: Mix of sun and cloud, light winds, alpine temperature around -7 C.TUESDAY: Cloudy with sunny periods and isolated flurries, light winds, freezing level climbs to 1500 m with alpine temperatures around -3 C.

Avalanche Summary

On Friday, a large cornice fall missed a group of skiers on a north aspect in the Duffey area (see MIN report for details). The previous day another skier remotely triggered a size 1.5 avalanche on a nearby south aspect at treeline. On Saturday, explosive control produced a few size 2-2.5 storm slabs and a few natural storm slabs were reported in the northern part of the region.On Sunday, storm slabs may remain reactive in human triggers. In northern parts of the region, the deeper February weak layers continue to present a low probability / high consequence scenario.

Snowpack Summary

Storm snow amounts on Saturday totalled roughly 40 cm around Coquihalla and Allison Pass and 30 cm around Duffey Lakes. Freezing levels reached roughly 1400 m, resulting in rain and/or wet snow at lower elevations. Thicker wind slabs and large cornices likely exist in alpine terrain. The storm snow sits above a widespread rain crust up to about 2100 m, but the snow will likely form a good bond to this crust. In the north of the region, the February weak layers are 80-120 cm deep and include a buried surface hoar layer that recently produced a few persistent slab avalanches and a crust/facet layer that appears to be gaining strength. In the southern parts of the region, the lower snowpack is generally stable.

Regions covered