Avalanche forecast

Jasper

Dec 12 – 13, 2020
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Avalanche danger

Sun
Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Despite the lack of natural activity, there is a lot of new snow present.  Remember Moderate means human triggering remains possible.

Avalanche problems

  • Wind Slabs

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

    Tuesday's 40cm storm had some moderate Southwest winds which loaded some slopes into windslabs. Caution is warranted despite the lack of natural activity.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–3

    The Nov. 4 crust is down 60cm to 80cm at tree line. Triggering a wind slab could potentially step down to this deeper layer creating large destructive avalanches. Be cautious of thick to thin snowpack areas being likely trigger locations.

Weather Forecast

Saturday will be clouds and sun, no snow, -9, and light winds. Sunday and Monday will be similar but colder at -17 to -8.

Snowpack Summary

40cm of storm snow from Dec 8th remains soft, continues to stabilize and settle. Wind-slabs only formed at exposed ridgetop features. The new snow overlies a variety of surfaces ranging from firm snow to surface facets and crusts on steep solar aspects. The depth of the Nov 4th rain crust is 60-80cm down and caps basal facets and depth hoar.

Avalanche Summary

Friday's patrol to climb Melt out on the Parkway observed no new avalanches. Thursday's patrol to Saskatchewan crossing noted no new avalanches. Visibility was excellent both days. Wednesday noted numerous loose dry natural avalanches size 1.5 and explosive control released only a few slab size 2 and one size 3 on a NE alpine feature.

Confidence

Due to the number and quality of field observations

Regions covered