Avalanche forecast

Jasper

Dec 12 – 13, 2023Avalanche Canada
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Archived · expired 3 years ago

Avalanche danger

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

Highlights

With strong winds on Saturday plus recent snow available for transport, be alert for dangerous avalanche conditions on specific terrain such as cross-loaded or wind-loaded slopes, Northwest to Southeast aspects, and where local terrain directs windloading patterns. Early season hazards are just below the surface.

Avalanche problems

  • Wind Slabs

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

    Winds were blowing 100km/hr on Saturday from the South but shifted light-moderate speeds from the Northwest Monday. Saturday's strong winds whipped the snow into lee aspect windslabs and intense spindrifts were observed in the weeping wall area.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2.5

    Failing on a buried preserved surface hoar, facet and melt-freeze crust layer roughly 20-50cm down. Slabs are stiffer and deeper where wind loading has occurred.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2.5

    The snow pack is very weak at the bottom. Last Tuesday's storm snow and recent building windslabs adds to its stress. Natural activity has not been observed yet keep this on your radar as triggering remains possible with the shallow nature of the overall snowpack.

Confidence

Moderate

Avalanche Summary

Monday's patrol to Beauty creek did not observe anything new. Sunday's patrol had limited visibility and the alpine was obscured. Three size 1-2 wind-slabs were observed in the Parker area where one would suspect the buried surface hoar was sheltered, present, and preserved. These appeared to have occurred on Thursday or Friday.

Snowpack Summary

30cm of new snow from last Tuesday formed a persistent slab overlying a surface hoar or facet layer or a melt-freeze crust on south and west aspects. The snowpack is 40-60cm deep with a weak facetted base. A rain crust exists below 1800m. Saturday's moderate to strong South winds spawned windslabs on lee aspects.

Weather Summary

The Mountain Weather Forecast is available from Avalanche Canada https://avalanche.ca/weather/forecast

Tuesday to Thursday will be a mix of sun and cloud, -4 °C, light Southwest winds. A weak temperature inversion should occur Tuesday - Wednesday.

Terrain and Travel Advice

  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Keep in mind that human triggering potential persists as natural avalanching tapers off.

Regions covered