Avalanche forecast

South Coast Inland

Jan 29, 2018Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Highlights

More warm, wet, and, windy weather in the forecast means that dangerous avalanche conditions will persist on Monday.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1.5–2.5
    Large amounts of new snow and high winds will create tender cornices sensitive to human triggers.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2.5
    New snow and wind will create another round of touchy storm slabs reactive to human triggers. Storm slab danger will likely increase with elevation, however rising temperatures and rain will promote loose wet avalanches at lower elevations.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3.5
    Intense loading of new snow may awaken deeply buried weak layers resulting in large, destructive avalanches.

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

Sunday night: Periods of snow bringing 20-30 cm of new snow. Heavy rain below about 1100 metres, possibly 1600 metres.Monday: Continuing periods of snow bringing 10-25 cm of new snow to higher elevations. Rain below about 1600 metres. Strong to extreme southwest winds Freezing level to 2000 metres with alpine temperatures around 0.Tuesday: Mainly cloudy with isolated flurries and a trace to 3 cm of new snow. Moderate to strong southwest winds. Freezing level to 1200 metres with alpine high temperatures around -4.Wednesday: A mix of sun and cloud with isolated flurries and a trace of new snow. LIght west winds. Alpine high temperatures of -7.

Avalanche Summary

Reports from Saturday showed recently formed storm slabs reactive to skier traffic and ski cutting, producing small (Size 1, 30-35 cm deep) storm slab and loose dry releases. Poor visibility was noted to be limiting observations.On Thursday, two natural storm slab avalanches stepped-down to facets at the bottom of the snowpack and resulted in Size 3-3.5 avalanches. They occurred on north and south aspects between 2000 and 2250 m. The extended period of continuous loading of the snowpack may begin to reactivate deeply buried weak layers resulting in large and destructive avalanches running full path.

Snowpack Summary

Another 10 cm of new snow on Sunday morning brings recent storm totals to 90-120cm. Moderate to strong south winds have been redistributing each day's accumulations into dense storm slabs in lee and cross-loaded features at treeline and above.90-120cm below the surface you'll likely find a few crusts that were buried during the first few weeks of January. Due to limited observations, not much is known about the current reactivity of these layers.The lower snowpack includes the mid-December crust layer. The load of the new snow may tip the balance and reactivate this layer in isolated terrain - particularly in the north of the region where it has shown prolonged reactivity in snowpack tests.

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