Bollettino valanghe

Purcells

Mar 18 – 19, 2012Avalanche Canada
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Archiviato · scaduto 15 years ago

Pericolo valanghe

Tue
Wed
Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
Apri la mappa completa

In sintesi

There is still a concern for strong solar warming in some areas. I don't think it will be widespread, but some southerly aspects may get their first warming since the recent storms.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    2–5
    Recent wind slabs are settling, but may take a couple of days to bond.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    4–8
    The deep nature of the mid-February surface hoar layer makes potential avalanches triggered on this layer large and destructive. Regular and ongoing avalanche activity associated with this layer indicates it is very much still alive.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–6
    Storm slabs continue to build and consolidate. The dense storm slab may be easily triggered by light additional loads. Solar radiation may trigger another round of natural activity.

Avalanche Summary

One operator reported that a snowcat remotely triggered a W-SW aspect slope in the alpine from 25 metres away that released on a persistent weak layer down close to 200 cm and resulted in a size 3.5. Explosive control on Saturday resulted in slabs that were 50-80 cm thick and up to size 2.0

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Monday

Weather Forecast

A ridge of high pressure with light winds and many sunny periods are expected on Monday over all of the interior regions. The airmass is still unsettled, and some areas may develop periods of convective flurries. A Pacific frontal system is forecast to move onto the coast during Monday evening, and should develop cloud and precipitation in the Interior around midnight. Expect winds to increase to moderate from the southwest and precipitation to be moderate to heavy by Tuesday morning. This system is expected to continue during the day and into Wednesday morning.

Snowpack Summary

Convective flurries resulted in another 10-20 cm of new snow across the region combined with light winds. There is a soft slab about 50 cm thick that is sitting on the recent storm snow. The combined slab above the mid-february persistent weak layer is now between 150-200 cm. Some operators continue to get easy-moderate sudden planar character shears on the mid-february surface hoar in shallow areas. The persistent weak layer continues to be a concern at all elevations, and may show wide propagations on low angle terrain below treeline. The new snow may consolidate and release naturally if the skies clear and we get some strong solar radiation. Snowpack conditions continue to be tricky to evaluate, and are variable throughout the region.

Regioni coperte