Bollettino valanghe

Purcells

Mar 19 – 20, 2023Avalanche Canada
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Archiviato · scaduto 4 years ago

Pericolo valanghe

Tue
Wed
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Apri la mappa completa

In sintesi

Use caution when transitioning into wind-affected terrain.

Stick to thick snowpack areas where you are less likely to trigger deep weak layers.

Problemi valanghivi

  • Wind Slabs

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

    Southwest wind has redistributed last week's snow at higher elevations.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1.5–3

    Numerous weak layers from January and February exist at all elevations on a variety of aspects. On shaded slopes, these layers generally present as surface hoar, and on sun-exposed slopes they present as facets and a crust.

    Be aware these layers can be remotely triggered (from a distance).

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2.5–4

    The base of the snowpack remains very weak. Very large human triggered avalanches are possible at treeline and above. Avoid thin, rocky start zones and shallow areas with variable snowpack where you are most likely to trigger this layer.

Confidence

Moderate

Avalanche Summary

A size 2 cornice avalanche was reported on Saturday. It occurred naturally in the alpine on a northwest aspect. It did not trigger the slope below.

On Friday, a few solar-triggered loose dry avalanches were reported in the region to size 2. A natural size 2.5 wind slab, likely triggered by the sun, was observed on a southwest aspect at 2500 m.

Explosives control triggered a deep persistent slab avalanche, size 2.5, on an east aspect at 2350 m.

Snowpack Summary

The top layer of the snowpack is made up of wind-affected snow in exposed areas and low-density snow in sheltered areas. This top layer sits on top of a varied of surfaces that include more wind-affected snow, facetted snow, and a thin sun crust. A sun crust is found on the surface of solar slopes at all elevations.

Buried surface hoar can be found 70 to 90 cm deep in sheltered terrain features. A thin sun crust exists at the same depth on steep south-facing terrain.

The lower snowpack is made up of a widespread layer of large, weak facets and/or depth hoar crystals. This weak layer has been responsible for a number of recent very large, destructive avalanches and will continue to be a concern.

Weather Summary

Sunday Night

Clear, no accumulation, winds east 25 km/h, treeline temperatures -3 to 0 °C.

Monday

A mix of sun and cloud, no accumulation, winds northeast 20 km/h, treeline temperatures around -5 °C freezing levels to 1700 m.

Tuesday

Sunny with cloudy periods, no accumulation, winds northeast 10 to 20 km/h, freezing level reaching 1700 m.

Wednesday

Sunny, no accumulation, winds northeast 20 km/h, freezing level reaching 2000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Avoid areas with a thin or variable snowpack.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Regioni coperte