Bollettino valanghe

Kakwa

Feb 1 – 2, 2023Avalanche Canada
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Archiviato · scaduto 4 years ago

Pericolo valanghe

Fri
Sat
Alta quota
4 · Forte
Limite del bosco
4 · Forte
Sotto il limite
3 · Marcato

In sintesi

New storm snow accompanied by moderate southwest winds will likely build fresh and reactive storm slabs through the forecast period. A small avalanche could step down to deeper weak layers.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–2.5

    New snow and strong wind will likely build reactive storm slabs through the forecast period. Storm and wind slab avalanches may step-down to deeper weak layers initiating large and destructive avalanches.

  • Deep Persistent Slabs

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

    A layer of large and weak facets sits near the base of the snowpack. This layer is most prominent in upper treeline and lower alpine elevations. As snow accumulates, the likelihood of natural and human-triggered avalanches increases. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain, or by triggering a smaller avalanche that could step down to this layer.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed on Monday. Many wind slab avalanches were triggered by riders and naturally last Saturday. They occurred on all aspects.

Looking forward, riders may trigger storm and wind slab avalanches in wind-exposed terrain as we receive new snow and strong wind throught he forecast period. Smaller avalanches could step down to the facets near the base of the snowpack, producing very large avalanches. See more on the potential of triggering deeper weak layers Forecasters' Blog.

The AvCan APP is LIVE! Please continue to send in your observations through the MIN.

Snowpack Summary

Up to 20 cm of fresh low-density snow may form new wind slabs in lee terrain features in wind-exposed terrain. The snow will rest on previously wind-affected snow. A melt-freeze crust is found near the snow surface on sun-exposed slopes and everywhere below 1600 m.

Several crust/facet/surface hoar layers exist in the upper and middle portions of the snowpack. Recent observations suggest these layers are not as concerning as in neighbouring regions.

The most concerning layer is at the base of the snowpack from large and weak facets formed in November. This layer is widespread and most likely problematic in steep, rocky alpine terrain.

Weather Summary

Tuesday Night

Cloudy new snow 10- 15 cm. Strong northwest wind at the ridgetop. Treeline temperatures steady -12 °C.

Wednesday

Cloudy with snowfall, accumulation 10-20 cm with local enhancements expected. Ridgetop wind moderate from the West and treeline temperature -12 °C.

Thursday

Cloudy with snowfall, accumulation 10 to 20 cm. Ridgetop wind light to moderate from the southwest. Treeline temperature -10 °C.

Friday

Cloudy with snowfall, accumulation 5 to 20 cm. Ridgetop wind moderate from the southwest and treeline temperatures warming to -5 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Uncertainty is best managed through conservative terrain choices at this time.

Regioni coperte