Avalanche forecast

Jasper

Jan 8 – 9, 2021
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Archived · expired 6 years ago

Avalanche danger

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

Highlights

Winds have diminished except for the very high alpine but the wind-slabs have formed from previous days. Natural avalanche activity has decreased yet conservative terrain selection is advised, assess every slope and human triggering remains possible. 

Avalanche problems

  • Wind Slabs

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

    Periodic SW winds continue to form wind slabs treeline and above. They appear to be stubborn with no natural activity observed the past 3 days but be vigilant for human triggering to remain possible. 

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3

    Use caution around thin to thick areas where buried deeper weak layers could be triggered. The surface hoar layer down 40-60cm seems unreactive and spotty distribution but keep it on your radar.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–3

    When the snowpack is thick, this weakness should be well bridged and less susceptible to triggering.  Triggering this deep layer would be low probability but high consequence.

Weather Forecast

Friday will be sun and cloud, flurries, -8C, and Light SW winds. Saturday will be similar, no new snow, -13C and light SW winds. Freezing level at valley bottom. Sunday will be clouds, sun, flurries, -12C, and light SW winds. There is no significant snow on the horizon.

Snowpack Summary

40cm of new snow from Jan 3rd continues to be redistributed by SW winds into wind-slabs mainly at exposed ridge-tops. This new snow overlies a sporadically distributed surface hoar and facet layer down 40-70cm. The mid-pack is supportive except in shallow locations. The bottom is weak facets and depth hoar.

Avalanche Summary

Thursday's patrol to the Icefield's noted one size 3, N-NE aspect, very high alpine, 1m thick and 300m wide on the backside of Mushroom peak. It is likely a very wind-loaded location. No patrol occurred on Wednesday. Tuesday's Hilda patrol had no new. Sunday's explosive control had varied results with some size 3's Use Mountain Information Network.

Confidence

Due to the number and quality of field observations

Regions covered