Bollettino valanghe

Glacier

Dec 23 – 24, 2023Avalanche Canada
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Archiviato · scaduto 3 years ago

Pericolo valanghe

Mon
Tue
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato

In sintesi

Fresh snow and wind will create a new reactive storm slab, watch for signs of instability.

A persistent weak layer of surface hoar mid-snowpack, is primed for human triggering. The safest way to manage this problem is through conservative terrain use.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    A weak layer of surface hoar down 50-100 cm in the snowpack is at the ideal depth for human triggering and remains reactive. To manage this problem, stick to conservative terrain. Below 2100m this layer may be bridged by a buried rain crust.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    New snow with wind will create a fresh storm slab. These avalanches have the potential to run far. Allow time for this snow to settle and bond before stepping out into committing terrain.

Confidence

Moderate

Avalanche Summary

Thursday/Friday, several natural avalanches up to size 2.5 were observed running from the steep terrain of Mt. Macdonald.

Significant human-triggered avalanches have occurred in the past week, all failing on the Dec 1st surface hoar layer. In the Connaught drainage a size 2.5 was triggered on Balu Peak, on Ursus Minor a skier narrowly avoided being carried over some cliffs, and in the Asulkan valley another avalanche was triggered near the 7 steps.

Snowpack Summary

High freezing levels have left moist snow up to ~2000m, this will form a crust as it cools. 15-25 cms of new snow has fallen over the last few days with wind creating wind slabs at ridgetop

The Dec 1 surface hoar, down 50-100cm, continues to produce 'sudden' results in tests and has been the culprit in several recent close calls from skier-triggered avalanches.

Below 2100m, a rain crust is buried 40-50cm deep.

In shallow areas the base of the snowpack is faceted and unsupportive.

Weather Summary

After Friday's storm we'll see high-pressure building, giving cooler temps and some sun.

Tonight: Trace precip, wind: westerly 20-30km/hr, Freezing level (Fzl) at VB

Saturday: Mix of sun/cloud. Temp: High -10°C, Winds: 15 gusting 40km/hr. Fz lvl 600m

Sunday: Mixed sun/cloud, Temp: High -6°C, Light South wind. Fz lvl 1000m

Monday: Mixed sun/cloud, Temp: High -7°C, light South wind. Fz lvl 1000m

Terrain and Travel Advice

  • Be mindful that deep instabilities are still present and have produced recent large avalanches.
  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.

Regioni coperte