Bollettino valanghe

South Columbia

Mar 25 – 26, 2013Avalanche Canada
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Archiviato · scaduto 14 years ago

Pericolo valanghe

Wed
Thu
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole

In sintesi

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    2–6
    Recent cornice growth is very large and weakly bonded. Large cornice falls may occur naturally or may be triggered by people travelling near to them.
  • 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. Large loads like cornice falls may trigger this deeply buried weak layer.
  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–4
    Pockets of windslab from localized wind, including downflowing katabatic wind, could be rider triggered. Periods of strong solar radiation may cause loose moist or wet snow to fall out of very steep terrain.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

The ridge of High pressure is expected to continue to influence the interior ranges for the next few days. As the ridge weakens we may see high cloud reducing the exposure to strong solar radiation. Nights are expected to continue to be clear and cool. Freezing levels in the North should rise during the day to about 1800 metres, and to about 2000 metres in the South. Some light precipitation may start to move in from the coast on Thursday afternoon.

Avalanche Summary

Cornice failures continue to be reported from several parts of the region. There were also a couple of dry slab and loose dry avalanches reported from alpine elevations. There was a skier accidental size 2.0 avalanche on Sunday in an adjacent region (Glacier National Park), that resulted in one fatality.

Snowpack Summary

Cornices are reported to be very large and weakly bonded. Natural cornice falls are a concern during daytime warming. Cornices may also be triggered easily by travelling near them. Slopes with corniced entrances, or exposed to cornice falls should be avoided with these conditions. Dry windslabs may be found on Northwest thru Northeast aspects at higher elevations. These wind slabs are reported to be improving their bond to the old surface, but may continue to be triggered by skiers and riders. Loose moist or wet snow may fall naturally out of very steep terrain on sun exposed slopes. Small loose snow avalanches may trigger the recent storm snow slab where it is moist from solar heating and sitting on a planar sliding surface like an old sun or rain crust. 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. The lower snowpack consists of well bonded layers that are well settled and strong.

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