Avalanche forecast

Jasper

Nov 19 – 20, 2021
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Avalanche danger

Sat
Sun
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low

Highlights

Natural avalanche activity has tapered off, but be conservative. There is still concern for human triggering.

Avalanche problems

  • Wind Slabs

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

    Watch for new wind loading at ridge tops and in the alpine as moderate SW winds are in the forecast and there is a lot of snow available for transport.

  • Storm Slabs

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

    Storm slabs are settling down but use caution and dig down to test the snow before committing to a slope.

Weather Forecast

Friday. Cloudy with sunny periods. Precipitation: Nil. High -9 °C. Ridge wind west: 15-35 km/h.

Saturday. Flurries. Accumulation: 6 cm. Low -12 °C, High -10 °C. Ridge wind west: 20 km/h gusting to 60 km/h.

Sunday. Mainly cloudy with isolated flurries. Precipitation: Trace. Low -12 °C, High -9 °C. Ridge wind southwest: 20 km/h.

Snowpack Summary

The 60-80cm of storm snow that fell over the past week continues to settle, and be redistributed by moderate southerly winds at ridge tops. This storm snow overlies variable basal snowpack depending on aspect and elevation with a melt freeze crust up to around 2500m, and weak faceted snow near the ground in most places tree-line and above.

Avalanche Summary

With good visibility on Wednesday numerous avalanches, up to size 3.5, were observed. Most occurred during and near the end of the past storm. These avalanches were predominantly out of steep alpine features, but a large avalanche was caused by explosives in a similar terrain feature at tree-line, propagating over 800m wide.

Confidence

Due to the number of field observations

Regions covered