Avalanche forecast

Lizard-Flathead

Dec 19, 2018Avalanche Canada
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Archived · expired 8 years ago

Avalanche danger

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

Recent snowfall has stressed the snowpack, leaving it primed for human triggered avalanches. Conservative terrain choices are recommended.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3
    A widespread weak layer is being stressed by the new snow and has the potential to produce large destructive avalanches.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2
    40 cm of new snow has left storm slabs primed for human triggering, especially on steep and wind loaded slopes.

Confidence

Moderate -

Weather Forecast

TUESDAY NIGHT: Lingering flurries could produce another 10cm of snow, strong wind out of the southwest, freezing level dropping to 1000m, alpine temperatures drop to -5c. WEDNESDAY: Flurries easing throughout the day with localized accumulations of 5cm, moderate wind from the southwest with strong gusts, freezing level up to 1200m, alpine high temperatures around -5c. THURSDAY: The next system arrives late in the day, strong wind from the southwest, freezing level climbs to 1500m, alpine high temperatures around -2c. FRIDAY: 10-20cm of snow, moderate wind from the northwest, freezing level drops to valley bottom with alpine high temperatures around -8c.

Avalanche Summary

Tuesday's storm produced natural storm slab avalanches in alpine terrain and numerous small skier triggered avalanches (size 1) on small steep slopes.On Saturday, a group of skiers remotely triggered a large (size 2) avalanche on a northeast facing slope at treeline in the Corbin area. The skiers were in dense trees and the avalanche released roughly 60 m above them. One skier was fully buried and the group successfully extricated them without significant injuries. For full MIN incident report follow this link.

Snowpack Summary

Tuesday's storm hit the region with 40 cm of new snow, forming fresh storm slabs at upper elevations. The precipitation fell as rain below 1500 m, leaving moist snow on the surface.Roughly 50-80 cm of snow now sits above a weak layer composed of large surface hoar, facets, and/or sun crusts. There have been numerous signs over the past few days that this layer remains weak (e.g. remote triggering from low angle terrain, wide propagations in avalanches), and the additional load of the new snow could be pushing this layer past the tipping point.Several other weak layers have been observed in the lower snowpack such as early season crusts with weak facets. The most concerning crust is prevalent at higher elevations and is likely most problematic on north-facing features, especially those that are large and planar in nature.

Regions covered