Avalanche forecast

South Rockies

Apr 15 – 16, 2017Avalanche Canada
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Avalanche danger

Mon
Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low

Highlights

Expect the avalanche danger to increase as the sun comes out and the temperature rises through the day.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3
    Cornices are most likely to trigger during periods of intense sunshine and/or the warmest parts of the day.
  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    The potential for prolonged periods of sunshine on Sunday will weaken surface snow especially on steep rocky solar aspects.

Confidence

Low - Due to the number of field observations

Weather Forecast

SUNDAY: Mix of sun and cloud / Light to moderate south wind / Alpine temperature -3 / Freezing level 1900mMONDAY: Cloudy with sunny breaks / Light south wind / Alpine temperature 0 / Freezing level 2100mTUESDAY: Cloudy with sunny breaks / Light to moderate southwest wind / Alpine temperature -1 / Freezing level 2000m

Avalanche Summary

Recent reports indicate several natural storm slab and cornice triggered avalanches to size 2 on all aspects tree line and above. Exposure to large overhanging cornices remains a significant concern. As the sun comes out over the weekend I would expect see cornices weaken and loose snow avalanches run from steep sun exposed slopes during the warmest parts of the day.

Snowpack Summary

Moist new snow falling last week above tree line has been redistributed by south and southeast winds. Cornices remain large and continue to become more overhanging. The middle of the snowpack is generally well settled and continues to transition into a spring melt/freeze regime. Expect the entire thickness of the snowpack to be moist or wet at lower elevations. At upper elevations, the bottom third of the snowpack is composed of weak facets, however there still is uncertainty to this layer's reactivity. That being said, a heavy load like a cornice fall or rapid warming of the snowpack could potentially trigger this layer.

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