Bollettino valanghe

Northwest Coastal

Mar 22 – 23, 2016Avalanche Canada
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Archiviato · scaduto 11 years ago

Pericolo valanghe

Thu
Fri
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Apri la mappa completa

In sintesi

The Avalanche Danger may change quickly in the spring. Even brief periods of sun or rain can trigger pushy loose wet avalanches or promote destructive cornice falls.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–3
    New snow and strong winds forecast for Wednesday will promote new wind slab formation in exposed high elevation terrain. New wind slabs are expected to increase in size and reactivity throughout the day.

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–5
    Natural cornice releases remain an ongoing concern for professionals in the region. During the past week, falling cornices have also triggered large avalanches on the slope below.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    3–6
    A few persistent weaknesses exist in the mid snowpack (see snowpack description). These potentially destructive layers may become reactive with spring warming or with a large trigger such as a cornice fall.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Wednesday

Weather Forecast

On Wednesday expect 5-12cm of new snow with strong southwest ridgetop winds. Continued light snowfall (5-8cm) and decreased winds are forecast for Thursday. Clearing skies are expected on Friday as a dry ridge of high pressure develops over the province. Freezing levels should hover between 1100 and 1200m for the forecast period.

Avalanche Summary

Loose wet avalanches to size 1.5 were reported to have occurred in steep terrain on a variety of aspects. They failed in response to periods of solar warming or rain. New wind slab activity is expected in response to new snow and strong winds on Wednesday.

Snowpack Summary

Light amounts of snow fell on Monday night. The new snow overlies older wind slabs in exposed terrain and settled powder on shaded, sheltered slopes. Spring conditions have continued to develop. With that, lower elevation and sun-exposed slopes will likely appear moist or refrozen. A layer of surface hoar or melt-freeze crust buried on March 3 is down 50-80cm and has been on the radar of professionals in the mountains north of Stewart. A more widespread crust/facet layer buried in early February can now be found down over a metre. Both of these deeper layers have become less likely to trigger, but have the potential for large avalanches especially with a large trigger such as a cornice fall. I'd be increasingly cautious during periods of warming or solar radiation.

Regioni coperte