Boletín de aludes

Northwest Inland

Jan 30 – 31, 2021Avalanche Canada
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Archivado · caducó 6 years ago

Peligro de aludes

Mon
Tue
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
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Lo esencial

Moderate to strong southerly wind will continue to build winds labs. These slabs are particularly reactive where they overlie surface hoar.

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible - Likely
    Tamaño
    1–2

    Moderate to strong southerly wind will redistribute loose snow and form fresh wind slabs in lee terrain features on northerly and easterly aspects. Older wind slabs were formed on westerly aspects on Wednesday and may still be reactive. Wind and soft slabs will be particularly touchy anywhere they overlie surface hoar that was reported to be widespread in many sheltered areas. 

    Loose snow avalanches (sluffs) are likely in steep and wind-protected areas and they might run longer and grow larger than expected. 

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

FRIDAY NIGHT: Cloudy, up to 6 cm new snow, moderate to strong southerly wind, treeline temperature -15 C.

SATURDAY: Mainly cloudy, up to 3 cm new snow, moderate southerly wind, treeline temperature -12 C.

SUNDAY: Mix of sun and cloud, trace of new snow, light to moderate southeast wind, treeline temperature -12 C.

MONDAY: Mainly cloudy, trace of new snow, light southwest wind, treeline temperature -12 C.

Avalanche Summary

A large natural dry loose avalanche was reported on Thursday. Fresh small wind slabs and sluffing on steep alpine slopes was reported on Tuesday. 

Isolated large avalanches failed during the weekend storm on recently buried surface hoar in the southwest of the region where recent snowfall amounts were on the higher end (up to 15 cm). A few cornice failures were observed late last week.  

Sporadic deep persistent slab avalanches were reported 1-2 weeks ago (triggered with heavy loads such as explosives and cornices), but deeper weak layers appear unreactive under the current conditions.

Snowpack Summary

5-20 cm recent low density snow has buried surface hoar, which was reported as widespread below treeline and isolated at sheltered treeline and alpine locations. A buried sun crust can be found on steep solar aspects. The new snow sits on widespread wind scoured surfaces, older wind slabs in alpine and exposed treeline locations and open wind effected areas below treeline. A thick crust exists near the surface below 1000 m. 

The lower snowpack has two decomposing crust layers that have been causing a deep persistent slab problem for most of the past month. The upper crust is 70-140 cm deep in the Smithers area and continues to show occasional hard sudden results in snow pits. The deeper crust at the bottom of the snowpack continues to be a problem in shallow ranges like the Babines. These layers should be unreactive under the current conditions, but shallow rocky slopes should still be carefully assessed and approached with caution. 

Terrain and Travel

  • Make observations and assess conditions continually as you travel.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Caution around slopes that are exposed to cornices overhead.
  • Watch your sluff: it may run faster and further than you expect.

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