Avalanche forecast

Jasper

Apr 10 – 11, 2017Parks Canada
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Archived · expired 9 years ago

Avalanche danger

Wed
Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate

Highlights

The slopes look inviting but Jasper Forecasters are still leery of big alpine slopes that have not seen ski traffic or previous avalanche activity. 

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3
    Cornice failure is hard to predict but likelihood increases with sun, warm temperatures, and wind-loading. There are some very large cornices out there. Wise to give them a wide berth.
  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–3
    Isothermal conditions are possible as crusts break down by late morning. Gauge the extent of the overnight freeze relative to how quick it will move into being reactive. 
  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–4
    The deep instability could be triggered by large loads such as a cornice failure or a surface avalanche. Human triggering is most likely from shallow spots or on steep unsupported slopes.

Weather Forecast

Tuesday and Wednesday nights will dip to -9 and warm up to -3 during the day. Winds may shift Easterly Tuesday night bringing 5-10cm of new snow by Wednesday morning.

Snowpack Summary

Good skiing above 2000m. Icefields has 10cm of soft snow on a solid mid-pack which bridges the weak base above 2000m. The base is a combination of weak facets and depth hoar mixed around a Nov rain crust. A consistent melt-freeze cycle is occurring below tree line. Surface crusts are breaking down by mid morning.

Avalanche Summary

No patrol Monday. On Sunday a couple sz 3 avalanches in steep un-skiable terrain NE alpine where cornice failure has triggered deep persistent slab.

Confidence

Regions covered