Avalanche forecast

Jasper

Jan 10 – 11, 2021
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Archived · expired 6 years ago

Avalanche danger

Mon
Tue
Alpine
2 · Moderate
Treeline
1 · Low
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
    Unlikely - 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 4 days but be vigilant for human triggering to remain possible. Most caution in the high alpine.

  • Persistent Slabs

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

    Use caution around thin to thick areas where buried deeper weak layers could be triggered. The surface hoar layer down 40-70cm 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

Sunday: Mainly cloudy with isolated flurries. High -7. Wind SW: 20-40 km/h.

Monday: Flurries. 8 cm. Low -8, High -6. Wind SW: 25 km/h gusting to 80 km/h

Tuesday: Periods of snow. Accumulation: 16 cm. Low -10, High -5. Wind SW: 20 km/h gusting to 45 km/h.

Snowpack Summary

The top layer is 40cm of new snow from Jan 3rd which has settled down to 20-30cm in sheltered spots or was redistributed by SW winds into wind-slabs at higher elevations. It 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

Saturday's flight and weather station service the team did not observe any new avalanches with excellent visibility and lots of terrain covered. Wednesday's patrol to the Icefield's had one size 3, N aspect, high alpine, 1m thick and 300m wide on the backside of Mushroom peak being a wind-loaded spot.  Use Mountain Information Network to report.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Monday

Regions covered