Avalanche forecast

Lizard-Flathead

Mar 4, 2018Avalanche Canada
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Archived · expired 9 years ago

Avalanche danger

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

The sun packs a powerful punch at this time of year. Consider the avalanche danger to be one step higher around slopes that see direct sunshine on Sunday.

Avalanche problems

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2
    Deep accumulations of new low density snow may continue to release easily in loose dry avalanches on Sunday. This may occur naturally in steep terrain, as well as with human triggers. Watch for terrain traps where sluffs can form deep deposits.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2.5
    All that new snow will need several days to settle and bond to the surface. As it does, natural avalanching will taper off while human triggering potential remains high. Stick to supported slopes and watch diligently for signs of slab formation.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

Sunday: A mix of sun and cloud with light flurries in the evening. Light southwest winds. Alpine high temperatures of -8.Monday: Mainly cloudy with isolated flurries and a trace of new snow. Moderate southwest winds. Alpine high temperatures of -10.Tuesday: A mix of sun and cloud. Light southwest winds. Alpine high temperatures of -10.

Avalanche Summary

Storm snow has grown touchy cornices and formed widespread soft storm slabs near ridge tops and open areas at treeline and below. On Thursday and Friday, explosives control in the Fernie area produced loose dry and storm slab releases reaching from size 1.5 to 2.5 with some slabs reaching up to 80 cm in depth.On Wednesday there were reports of several natural and skier triggered size 1 loose, dry storm snow releases on all aspects above 1700 m, as well as a few size 2-2.5 natural storm slab releases on northeast aspects that where possibly cornice triggered.Tuesday a size 2.5 natural storm slab release that was likely triggered by a cornice collapse, was reported on a northerly aspect in the alpine. Cornice collapses up to size 1.5 were also reported but did not produce slab releases on the slopes below.

Snowpack Summary

50-60 cm of new low density snow accumulated in the region over Friday night. This brings snowfall totals from the past week to about 100 cm. This storm snow overlies various old surfaces including old hard wind slabs, crusts, facets and more isolated surface hoar. Also in the upper to mid snowpack, a surface hoar layer buried mid-February is now 80 to 100 cm below the surface on sheltered northerly aspects.Deeper in the snowpack, the widespread mid-December weak layer sits about 200 cm deep. This consists of a crust, facets or surface hoar.Near the base of the snowpack, a crust/facet layer could be awoken from a thin-spot trigger point, or with a very large load like a cornice fall.

Regions covered