Bollettino valanghe

Kootenay Boundary

Mar 29 – 30, 2013Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 14 years ago

Pericolo valanghe

Sun
Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Apri la mappa completa

In sintesi

Danger could INCREASE TO CONSIDERABLE with intense radiation on south and west aspects, especially at treeline and below. Be aware of how the warm weather is changing the snowpack.

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    2–5
    With solar radiation and warm daytime temperatures, cornices may become unstable. There is a chance the weight of a cornice dropping onto the slope below could trigger an avalanche on the Mid-March crust.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    2–6
    Slab avalanches have been reactive to human triggering. The weak interface being the Mid-March crust down 40-60 cm below the surface. It may be more reactive in areas that have been slightly affected by the wind.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely - Certain
    Dimensione
    1–4
    Solar aspects are likely to see loose wet avalanches when the sun comes out and temperatures start to warm.

Confidence

Good

Weather Forecast

Saturday/Sunday: The high pressure system digs deeper! Winds remain light under clear, sunny skies. Alpine temperatures climb to 5 degrees each afternoon with freezing levels reaching 2600m.Monday: The ridge should begin to break down. Skies will remain mostly clear, light westerly winds should begin to blow and alpine temperatures will climb to just above freezing.

Avalanche Summary

On Wednesday, numerous loose wet avalanches up to size 2 were reported East through West aspects at all elevations. Be aware of overhead hazards such as cornice fall. It is likely that natural loose wet, or wet slab avalanche activity will persist through the weekend.

Snowpack Summary

Large cornices loom over many slopes. Cornice fall can act as a large trigger on slopes below, and may trigger a deeper instability if it exists. The upper 10-30cm of surface snow has become moist up to 2300 m, and melt-freeze crusts exists on solar aspects. On Northerly aspects surface hoar growth (up to 12 mm) and surface facetting is occurring.A cohesive slab overlies an old crust (down 50-60 cm) which exists up to ridge top. The crust appears to have gained some strength in most places, and some test results are showing resistant planar fracture characteristics. This layer may be harder to trigger, but should remain on your radar. It may be triggered by larger loads or skiers or riders hitting the sweet spot from a thinner snowpack area. With the weekend warm-up, wet slab avalanches may initiate naturally on this crust. Deeper down, another buried surface hoar layer sits approximately 80 cm. In some places it may not be a concern due to the thick supportive crust that lies above it. Because snowpack variability exists, it is important to dig down and test weak layers before diving into your line.

Regioni coperte