Boletín de aludes

Purcells

Nov 24 – 25, 2013Avalanche Canada
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Archivado · caducó 13 years ago

Peligro de aludes

Tue
Wed
Alta montaña
3 · Notable
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil

Lo esencial

You need to be the detective. Dig down, test weak layers and watch rising alpine temperatures. Feel free to send your observations to [email protected].

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–3
    Recent ridgetop winds have formed wind slabs on the lee of terrain features and slopes.
  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    2–5
    The probability of triggering a persistent slab may be decreasing; however if triggered, the consequence would be high. Watch shallower, thin-spot trigger points.

Confidence

Poor - Due to the number of field observations

Weather Forecast

An upper ridge of high pressure will remain over the Interior regions. At higher elevations (1600-2800m) an above freezing layer will persist through Tuesday and be pushed out by Wednesday. Monday: Mix of sun and cloud. Alpine temperatures near 0 degrees. Freezing levels rising to 2600 m. Light-moderate ridgetop winds from the West. Tuesday: Mix of sun and cloud. Alpine temperatures -1. Freezing levels 2000 m. Light westerly ridgetop winds.Wednesday: Mainly sunny. Alpine temperatures -5. Freezing levels dropping to 1500 m. Light westerly winds.

Avalanche Summary

No recent avalanche activity has been reported. The weight of a person easily triggered persistent slab problems last week. The likelihood of triggering may be decreasing, however the consequences would be huge.

Snowpack Summary

The average snowpack depths at treeline sit 70-100 cm and near a metre or more in the alpine. A surface hoar layer has been found in the Columbias 60-120 cm down and seems to be spotty, and drainage specific. I'm not sure if it exists in the Purcells. Have you seen any? Deeper in the snowpack near the base is a melt-freeze / rain crust that formed in October. This is generally found 70-110 cm down, with facetted (sugary) crystals above and below that are poorly bonded. The crust/ facet combo may be more predominant on Northerly aspects and allow for wider propagations, especially in places that have smooth ground cover (glacier ice, grassy slopes, rock slabs etc.).Snowpack conditions may change and deteriorate if temperatures rise in the alpine.

Regiones cubiertas