Avalanche forecast

South Columbia

Feb 9, 2017Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
4 · High
Treeline
3 · Considerable
Below
3 · Considerable

Highlights

Keep watching for signs of instability and changing conditions as you gain elevation. The conditions still require conservative terrain selection. Wind exposed areas are the most concerning.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–3
    Heavy loading from snow and wind is expected to result in natural storm slab avalanches. Storm slabs are expected to remain highly sensitive to human triggers, especially on unsupported slopes and where wind and sun has promoted slab formation.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

THURSDAY: Mainly cloudy with 15-25 cm of fresh snow, moderate to strong southerly winds, and freezing level near valley bottoms.FRIDAY: Cloudy with scattered flurries bringing approximately 5 cm of fresh snow, moderate to strong southwesterly winds, and freezing level remaining at valley bottoms.SATURDAY: A mix of sun and cloud with isolated light flurries possible, moderate westerly winds, and freezing levels below valley bottoms.

Avalanche Summary

Reports of natural and human triggered storm slab avalanches up to Size 2.5 continues, with some slabs exhibiting wider propagation than seen in previous days. Storm slabs are expected to remain sensitive to light triggers and heavy loading from snow and wind is expected to result in continued natural avalanche activity. Loose snow avalanches have also been an ongoing hazard for the past few days and should not be underestimated in steeper and confined terrain, especially where the potential exists to entrain significant mass.

Snowpack Summary

Fresh snow totals from the past few days to a wide-ranging 40-90 cm, with the highest amounts near the crest of the Selkirks in the western part of the region. This recent storm snow has settled into a slab, especially where it has been wind-loaded or warmed by the sun, which is bonding poorly to the previous snow surface that includes sun crust on steep sun-exposed slopes, faceted snow, as well as surface hoar on sheltered open slopes. Weaknesses are also lingering within the recent storm snow, with several easy to moderate shears being reported. A persistent weakness buried mid January is now down 50-120 cm and consists of buried surface hoar in sheltered areas, sun crust on south aspects, and/or widespread faceted old snow. It has generally stabilized but may be sensitive to triggering in isolated areas where buried surface hoar is preserved. The mid and lower snowpack are generally well settled and stable.

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