Bollettino valanghe

South Columbia

Mar 27 – 28, 2013Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 14 years ago

Pericolo valanghe

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

In sintesi

Be aware of changing conditions with daytime warming and sunny skies. Watch solar slopes and overhead hazards. 

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    2–6
    Natural cornice falls are a concern during daytime warming. Cornices may also be triggered easily by traveling near them. Slopes with corniced entrances, or exposed to cornice falls should be avoided with these conditions.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    3–6
    The March 10th weak layer of surface hoar is buried down more than a metre in most places. Pockets of wind slab from localized wind, including down-flowing katabatic wind, could be rider triggered.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–4
    Periods of strong solar radiation may cause loose moist or wet snow avalanches. Keep an eye on changing conditions: Snowballing, moist and wet surface snow are all  initial indicators of deterioration.

Confidence

Good

Weather Forecast

A split-flow pattern will be keeping things fairly benign; the most significant change through the forecast period will be warmer temperatures (above seasonal norms), higher freezing levels and intense solar radiation. The region will likely see more cloud cover come Friday.Thursday:  Few clouds. Alpine temperatures near 1.0 degree. High diurnal temperature swings up to 2000 m in the afternoon. Ridgetop winds will blow light from the West.Friday: Scattered cloud cover. Alpine temperatures near 3.0. Freezing levels 2100 m and ridgetop winds light from the West.Saturday: Few-scattered cloud clover. Alpine temperatures -3.0 and freezing levels 1500 m. Ridgetop winds light from the NW.

Avalanche Summary

Natural cornice failures and wet-loose avalanche up to Size 2.5 continue to be reported from throughout the region. One size 4.5 slab avalanche was reported from the North Columbia region. This was a cornice fall triggering multiple persistent weak layers deeper in the snowpack. This avalanche activity is expected to continue with warm and sunny weather throughout the forecast period.

Snowpack Summary

Surface faceting and surface hoar growth has been prevalent on shady slopes and at upper elevations, while the surface snow on sun-exposed slopes and at lower elevations has been subject to daily melt-freeze cycles. Cornices are reported to be very large and weakly bonded. Cornice fall has been responsible for triggering some persistent weak layers below and initiating some very large avalanches.Wind slabs are reported to be strengthening, but may continue to be sensitive to human-triggers. The weak layer of buried surface hoar from March 10th is down more than a metre in most places, and is giving variable results in snow profile tests. However, this deep persistent weakness remains a concern.

Regioni coperte