Avalanche forecast

Jasper

Dec 26 – 27, 2021
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Archived · expired 5 years ago

Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate

Highlights

Happy Holidays to everyone from Jasper Visitor Safety!Should you brave the cold, be vigilant for new wind slabs.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2

    Up to 35cm of new snow Dec 22-23rd with moderate to strong winds created wind slabs on lee and cross loaded features. Slab development can be found low in terrain features. A rain crust 30cm down is a suspect weak layer in BTL wind affected snow.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    A Dry loose problem will persist for the short term particulary from steep terrain.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3

    This problem, although stubborn, persists in isolated alpine terrain and can initiate with a large trigger or rapid loading. Use extra caution in thin areas were humans are most likely to trigger this high consequence layer.

Weather Forecast

Sunday will be sun with mixed clouds and flurries, a trace of new snow, -28C, and light East winds. Monday will be similar with slightly warmer temperatures. Tuesday may have more sun but remain frigid.

Snowpack Summary

35cm of snow arrived Dec 22-23 with moderate to strong SW winds. Wind slab developed in the alpine and on exposed terrain features at treeline. The mid-pack is generally supportive with an exception of a weak rain crust 30-40 cm down found up to 1950m. Cold temperatures will accelerate faceting.

Avalanche Summary

Friday's avalanche control produced numerous 30cm thick wind slabs up to size 2 on wind loaded open tree line features. One result buried the road 2m deep for a 100m. Surprisingly, explosive triggers did not trigger the deeper instabilities. Numerous dry loose resulted from explosives and natural activity also occurred up to size 1.5.

Confidence

Due to the number and quality of field observations on Sunday

Regions covered