Bollettino valanghe

South Columbia

Dec 23, 2017Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

Sun
Mon
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
Apri la mappa completa

In sintesi

Where there is uncertainty in the snowpack, conservative terrain is the answer. Check out today's Forecaster's blog for tips on managing the spatial variability associated with our current persistent slab problem. LINK

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–3
    Shifting winds since the storm have been redistributing new snow into wind slabs on a variety of aspects. The most recent of these are the result of Friday's north to northeast winds. Keep this reverse loading pattern in mind as you gain elevation.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    2–3
    Reactivity at the buried December 15 interface will likely be greater where the new snow has settled into a cohesive slab above buried surface hoar. Use extra caution in wind affected areas and around steeper, sheltered slopes at treeline and below.

Confidence

Moderate -

Weather Forecast

Saturday: A mix of sun and cloud. Light northwest winds. Alpine temperature of -16.Sunday: Mainly sunny. Light west winds. Alpine temperature of -13.Monday: A mix of sun and cloud. Light northwest winds. Alpine temperature of -17.

Avalanche Summary

Reports from the past few days include explosives controlled and natural storm snow avalanches to size 2.5 in the alpine and tree line. There have also been a several reports of skier accidental and skier remote (triggered from a distance) avalanches to size 1.5 at and below tree line. Slab avalanche activity can be expected to persist or possibly increase as our recent snow consolidates into a slab above the range of weak surfaces present at the December 15 interface. In areas where new snow has not yet consolidated into a slab, expect continued potential for triggering loose dry avalanches in steep terrain.

Snowpack Summary

Stormy weather over the past week has brought 50-80cm of new snow to the region. The new snow lies over a wide variety of old surfaces, including large surface hoar (weak, feather-like crystals), hard crusts formed by sun or wind, and sugary facets. The bond at this old snow interface becomes critical as the overlying snow gradually consolidates into a slab. The most concerning areas areas will be those that have seen previous surface hoar development, such as sheltered areas at and below tree line and sheltered northerly aspects in the alpine. Additionally, any steep solar aspects where surface hoar may be sitting on sun crust should be considered areas where this weak layer may be more likely to trigger. A crust which was formed by rain in late November is a major feature in the snowpack and is down approximately 90-120cm at tree line elevations. Snowpack tests suggest the snow above is currently bonding well to it. Snowpack depth decreases rapidly below tree line. Look out for early season hazards such as rocks, stumps, and open creeks.

Regioni coperte