Bollettino valanghe

Banff Yoho Kootenay

Mar 5 – 6, 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
2 · Moderato

In sintesi

Wind slabs remain reactive to human triggering. Watch for wind loaded features in the alpine and at treeline.

Problemi valanghivi

  • Wind Slabs

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

    Numerous reports of wind slabs remaining reactive in lee features. Stay judicious in these areas with new snow/wind. Solar radiation has started to affect the snowpack during the heat of the day. Be mindful around extreme terrain and terrain traps.

  • Persistent Slabs

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

    Three persistent weak layers formed in January are down 60-100 cm. The biggest concern is triggering these buried suncrusts on steep solar slopes, but weaker facets and isolated surface hoar can be found on the same interface on shaded aspects.

  • Deep Persistent Slabs

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

    Weak facets and depth hoar are present at the bottom of the snowpack which inspires very little confidence. Be especially cautious in thin snowpack areas, which are likely areas for triggering. Natural activity is still happening on this layer.

Confidence

Moderate

Avalanche Summary

Ski hills are still reporting wind slabs being reactive to skier/boarder traffic up size 1.5 in lee aspects at all elevations. Several cornices failures to size 2 have also been reported in the last 24/48h. Recent natural activity has also been observed on the basal facets in the last 24h, up to size 2.5

Snowpack Summary

The alpine and exposed regions at treeline are wind effected and have windslabs which remain active to human triggering. Steep solar slopes at treeline and below may also have a thin sun crust. The wind slabs overlie the various Jan PWL interfaces of sun crusts, facets, and surface hoar down 65-120 cm. The weaker Nov. 16 basal facet layer is down 50-200 cm and produces moderate to hard sudden collapse results. Deeper snowpack areas west of the divide are stronger and more supportive than areas to the east.

Weather Summary

Saturday Evening: An upslope front could bring 5cm's to the eastern regions of the park, as overnight lows drop to -15/-20.

Sunday: Expect a mix of sun and cloud with trace amounts of snow through the day. Winds will be SE to S at ridgetop, avg. 20-30 km/h with gusts in some areas to 50km/h. The daytime high in the alpine is forecast to be -10.

For a more detailed weather forecast, click here.

Terrain and Travel Advice

  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Regioni coperte