Avalanche forecast

South Coast

Apr 7 – 8, 2014Avalanche Canada
View on map
Archived · expired 12 years ago

Avalanche danger

Wed
Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
Open full map

Highlights

Check out the new Forecaster Blog and gain insight of how to manage cornices, and how warming influences the snowpack.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    Strong SW winds have set up wind slab problems on leeward slopes, behind ridge crests and mid slope features like ribs/rock outcroppings. Sagging cornices may become weak with warming and solar radiation.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–3
    With warmer temperatures, limited overnight re-freeze and rain forecast, loose wet avalanches are likely.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    3–7
    Three buried weak layers exist in the snowpack. Deep releases have become rare; however, the weak layers could be activated by cornice fall, a surface avalanche in motion, or intense loading from snow, and wind.

Confidence

Fair - Intensity of incoming weather systems is uncertain on Tuesday

Weather Forecast

Precipitation and strong SW winds will prevail as the cold front moves across the region Tuesday. Tuesday: Mainly cloudy with snow up to 10 cm. Freezing levels 1900 m then dropping overnight to valley bottom. Ridgetop winds moderate from the SW. Wednesday: A mix of sun and cloud. Ridgetop winds light from the West. Freezing levels near 1300 m. Thursday: Mainly cloudy and some flurries expected. Ridgetop winds light from the West. Freezing levels near 1300 m.

Avalanche Summary

Small loose dry avalanches were seen from steep rocky terrain features. Loose wet avalanches were also seen on solar aspects. I suspect natural activity will continue with the warmer temperatures and insignificant overnight re-freeze. Smaller surface avalanches may trigger deeper weak layers, especially in thinner snowpack areas.

Snowpack Summary

Up to 20 cm of new snow sits above a mix of surface hoar, facets and melt freeze crusts. The new snow seems to have a poor bond to old surfaces and isolated wind slabs likely exist. Warmer temperatures and rising freezing levels will likely weaken the snow surfaces and become moist or wet.Recent warm temperatures have helped to settle and strengthen the upper snowpack and snowpack tests have been producing hard resistant planar shears on the late March crust down 30-50 cm.The persistent weak layers from early March and early February continue to be a concern. The March melt-freeze crust/surface hoar is reported to be down 60 - 100cm. The February crust/facet/surface hoar layer is now deeply buried down 150 - 250cm. These layers are mostly inactive at this time, but could re-awaken with extended warming, solar influence and precipitation through the forecast period.

Regions covered