Bollettino valanghe

Yukon

Jan 17 – 18, 2025Avalanche Canada
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Archiviato · scaduto 2 years ago

Pericolo valanghe

Sun
Mon
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
Senza grado

In sintesi

Stick to simple terrain and avoid overhead slopes. It's possible to remote-trigger very large avalanches from long distances away.

Check out this MIN report showcasing a recent avalanche.

 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1.5–2.5

    Reactive wind slabs may exist. North through east slopes are very loaded with deep deposits of snow but changing winds could also load south facing slopes on Friday.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    2–3.5

    A layer of facets over a crust buried 60 to 100 cm deep and if triggered will produce large and destructive avalanches.

Confidence

Moderate

Avalanche Summary

On Wednesday, the Yukon Team via snowmobile remotely triggered a large (size 3) persistent slab avalanche from 100 m away near Bryant Lake. It was triggered from flat terrain at the col on an ENE aspect at 1500 m. The crown depth was 1 to 2 m, the width was 400 m and it ran 400 m down slope. It slid on the December facet/ crust interface.

A natural avalanche cycle up to size 3 occurred during the storm earlier in the week.

Human-triggered avalanches remain likely on Friday.

Snowpack Summary

Up to 40 cm of storm snow has been redistributed by strong southwest winds building thick wind slabs on leeward slopes.

A persistent weak layer consisting of a crust with faceted snow above it is buried 60 to 100 cm, and extends up to 1750 m. Recent snowpack tests have shown moderate results with sudden collapse behaviour. A large (size 3) remotely triggered avalanche is an indicator that this persistent slab is reactive.

Total snow depths are around 160–190 cm at treeline.

Weather Summary

Thursday Night

Clear. 15 to 40 km/h northwest ridgetop wind. Treeline temperature -18 °C.

Friday

Mix of sun and cloud. 15 to 20 km/h southwest ridgetop wind. Treeline temperature -10 °C.

Saturday

A mix of sun and cloud. 20 km/h southwest ridgetop wind. Treeline temperature -9 °C.

Sunday

A mix of sun and cloud. 10 to 25 km/h southwest ridgetop wind. Treeline temperature -8 °C. Strong alpine above freezing layer.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Remote triggering is a concern; avoid terrain where triggering overhead slopes is possible.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
  • In times of uncertainty, conservative terrain choices are our best defense.

Regioni coperte