Avalanche forecast

Banff Yoho Kootenay

Apr 9 – 10, 2013Parks Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate

Highlights

If the storm arrives as forecasted, avalanche danger will rise on Wednesday.  Be cautious of overhead hazard as natural avalanche activity is likely from steep alpine terrain.

Avalanche problems

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Increased winds today caused numerous loose dry avalanches in steep alpine terrain. Forecasted new snow, winds and warming temps will increase activity in this terrain. This is of particular concern for climbers or skiiers entering steep couloirs.
  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    The forecasted precipitation, winds, and increased temps will create new storm and windslabs that will be most reactive during the storm. Natural activity will decrease once the system passes, but the newly formed slabs will take a few days to settle

Weather Forecast

A system is approaching on Wednesday and is forecasted to bring 10-20 cms with M-S SW alpine winds and freezing levels to 1800m.  On Thursday, the storm eases with only a few cms. cooling temps, and easing winds. Friday is looking relatively clear, with cool temps and light winds.

Snowpack Summary

Cold temperatures have tightened the snowpack, creating a supportive crust at lower elevations. In the alpine and at treeline, convective storms have dropped 10 - 30 cm of new snow which sits on top of suncrusts on solar aspects and old facetted snow on polar aspects. In some areas, windslabs may exist, although the winds have been mostly light.

Avalanche Summary

A field team in the White Pyramid area on the 93N remote triggered a small, thin windslab of little consequence in the alpine today.  Reports indicate increased winds were causing numerous loose dry avalanches out of steep alpine terrain.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Wednesday

Regions covered