Boletín de aludes

South Rockies

Jan 11 – 12, 2012Avalanche Canada
Ver en el mapa
Archivado · caducó 15 years ago

Peligro de aludes

Fri
Sat
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
Abrir el mapa completo

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–4
    New snow and generally localized winds have set up wind slabs in the immediate lee of ridgelines and other exposed terrain features.

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–6
    At least two distinct surface hoar layers lie buried up to 80 cm below the snow surface. Triggering these layers has become difficult and isolated to steep, shallow rocky start zones; however the destructive potential of a slide is high.

Confidence

Good - -1

Weather Forecast

Thursday should remain dry with a mix of sun an cloud. Treeline temperatures should be around -8C. Winds light westerly. Friday should see similar conditions, although freezing levels will rise to around 1000 m in the afternoon. On Saturday, a frontal band sweeps across the region. However, only light snowfall or flurries are expected. Freezing levels are expected to be around 500 m.

Avalanche Summary

One size 2.5 natural slab avalanche occurred in the Elk Valley on a NE aspect at around 2200m on Tuesday. The fracture depth was 30-40 cm. Additionally, small loose snow avalanches were also reported from the region on Tuesday in the new snow. A sled-triggered size 3 slab avalanche was reported from the Flathead/ Lodgepole area on Saturday. The slide was 75cm deep and 100m wide and occurred on a northeast aspect at the 2100m elevation.

Snowpack Summary

The average HS (height of snow) in the Crowsnest North is 130cms and the Crowsnest South has 160cms. As we move further West into the Elk Valley North the HS is an average of 140cms. The Elk Valley South sits at 180cms.In the Flathead the avg. HS is 180cms. All snow depths indicated are at the 2000m elevation.A nice dump of around 20 cm of low density new snow arrived Monday night. Winds have remained fairly light, although I would expect some wind loading in exposed areas in immediate lee areas down from ridge lines. The upper slab is still relatively unconsolidated - the cooler temperatures will maintain this situation for a little while to come.In the mid pack, weak buried surface hoar layers can be found on North-NE slopes at treeline and below down approx. 30-55cms. The surface hoar may co-exist with facets that are result of the early December dry spell. This interface is still reactive and has produced numerous natural avalanches over the past week.At the bottom of the snowpack a variable facet/ crust/ facet sandwich is located with depth hoar up to size 5mm below the crust, and facets size 2mm above. There has been little in the way of recent activity on basal layers, but the nature of a release would be highly destructive.As a side note, the snow depths alone indicate that the region is highly variable in terms of snowpack structure. You should anticipate that layering and reactivity of weaknesses will also be variable throughout the region.

Regiones cubiertas