Avalanche forecast

Northwest Coastal

Apr 10 – 11, 2018Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

New snow and strong winds will form storm slabs at upper elevations, while lower elevations are likely to receive rain. Be aware of conditions that change with elevation as you transition from wet to new snow.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5
    New snow may bond poorly to an underlying crust. Watch for fresh storm slabs in leeward areas near ridge crests and convex features, as well as loose snow releases in steep terrain.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Sun and daytime warming are factors to keep in mind. Watch for wet snow on sunny aspects and lower elevation slopes, especially in the afternoon.

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

TONIGHT: Flurries. Accumulation 10-15 cm. Ridge wind strong to extreme, south. Alpine temperature near -2. Freezing level lowering to 800 m.WEDNESDAY: Mostly cloudy, flurries. Accumulation 5-10 cm. Ridge wind strong to extreme, southeast. Alpine temperature near -2. Freezing level 1200 m. Snow beginning in the evening.THURSDAY: Mix of sun and cloud, flurries ending. Accumulation 5-10 cm. Ridge wind moderate, south. Alpine temperature near -5. Freezing level 1100 m.FRIDAY: Mostly cloudy, snow. Accumulation 10-20 cm. Ridge wind moderate, south. Alpine temperature near -5. Freezing level 1100 m.

Avalanche Summary

Northern parts of the region reported that; warming on Sunday and Monday produced a natural, loose, wet avalanche cycle up to size 2 on all aspects up treeline and in steep alpine terrain. Last week, the Shames area saw a widespread natural cycle up to size 3 on solar aspects as a result of Friday's storm. See recent MIN report. While further north only isolated wind slab and loose, wet activity was reported. Read MIN report.On Thursday northern parts of the region saw a widespread natural avalanche cycle triggered by strong to extreme wind loading event in the alpine. There was also a report of an icefall triggered size 2.5 slab avalanche that failed on the mid-March interface, northwest of Meziadin Lake.

Snowpack Summary

Rain and warming to ridge top elevations have created wet or moist snow in the top 20-30 cm of the snowpack that is likely to be covered by a light dusting of new snow by Wednesday morning. Only high alpine, north aspects (above 2000 m) may still be harboring dry snow. In the south of the region, two layers of surface hoar are buried approximately 70-100 cm deep. The layers are most prominent on north to east aspects and were buried early-March and mid-March. In the north of the region, these layers are around 40 cm deep.Bellow these March layers the mid-pack is generally well-settled and strong. However, shallower parts of the region, such as the far north, have weak sugary facets near the bottom of the snowpack.

Regions covered