Avalanche forecast

Northwest Coastal

Dec 27 – 28, 2018Avalanche Canada
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Avalanche danger

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

Avalanche Hazard will rise through the day as snow falls. If over 30 cm of snow accumulates, avalanche hazard will be HIGH.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2.5
    More snow will form new slabs, and bury and add load to older wind slabs. Deeper and more sensitive deposits of snow will likely be found at higher elevations and in lee-features, these are the most suspect for human triggering.

Confidence

Low - Intensity of incoming weather systems is uncertain on Friday

Weather Forecast

THURSDAY NIGHT: Isolated flurries, 5-15 cm accumulation. Moderate southwest wind. Freezing level 700 m.FRIDAY: Snow, 20-40 cm accumulation. Moderate southwest wind. Freezing level rising above 900 m.SATURDAY: Snow, 10-30 cm accumulation. Variable west wind gusting strong to extreme. Freezing level dropping below 600 m. SUNDAY: Cloudy with isolated flurries, trace to 5 cm accumulation. Light west wind with strong gusts. Freezing level 700m.

Avalanche Summary

Last Sunday, explosives were able to trigger wind slab avalanches to size 1.5. Additionally, a large (size 2) natural wind slab avalanche was observed on a northeast aspect. On Monday, wind-loaded pockets were reactive to skier traffic, including 2 very small unsupported pockets remotely triggered (from a distance) by skiers.There have been no recent avalanches reported, however information from this region is limited. Tell us what you see by posting to the Mountain Information Network MIN.

Snowpack Summary

Up to 25 cm of new snow sits on a melt-freeze crust at elevations below approximately 1000 m. Above 1000 m, this new snow is just adding to the 150+ cm snowfall through December. Recent winds redistributed snow. Wind slabs are present at upper elevations, especially in lee and cross-loaded features. Expect to find more reactive slabs in wind loaded areas, and especially in places that receive higher snowfall amounts.A total 100-200 cm snow sits on a weak layer of surface hoar (feathery crystals), facets (sugary snow), and crusts. This layer was initially a concern when snowfall first accumulated, but the strength of this layer has generally improved. The surface hoar is most prevalent and has most recently been reactive between 1100-1300 m in more northern portions of the region, and is something to keep in mind if you plan to travel to areas like Ningunsaw.Deeper in the snowpack, there are several crusts, including an early season crust with facets near the bottom of the snowpack.

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