Bollettino valanghe

Purcells

Dec 19 – 20, 2022Avalanche Canada
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Archiviato · scaduto 4 years ago

Pericolo valanghe

Wed
Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato

In sintesi

Although avalanche activity has tapered off, buried weak layers are still reactive to rider triggering.

Cold temperatures and shorter days should play a role in your trip plan.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1–1.5

    Wind slab could be found on all aspects in the alpine. These slabs could be more reactive where they overlie facets. If triggered their likely hood of creating large avalanches is high if they "step down" to buried weak layers.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    A layer of surface hoar, facets and a crust from mid november is buried around 40cm deep but can be found down as much as 80 cm. This layer is most likely to be rider triggerable on slopes at treeline where the snow above feels stiff and consolidated. Avalanche activity on this layer has been decreasing over the week but it's not likely to go away with the continuing cold temperatures.

Weather Summary

Sunday Night

Cloudy, up to 2 accumulation, 10 to 15 km/h northeast wind, temperature -25 C at 1500 m.

Monday

A mix of sun and cloud, trace accumulation, 10 km/h northeast winds, temperature -25 C at 1500 m.

Tuesday

Sunny with cloudy periods, no accumulation, 15 km/h southeast wind, temperature -20 C at 1500 m.

Wednesday

Mostly sunny, no accumulation, 10 km/h northwest winds, alpine temperature of -25 to - 30 C.

More details can be found in the Mountain Weather Forecast.

Confidence

Moderate

Avalanche Summary

Avalanche control continues to trigger the mid-November weak layer, producing up to size 2 avalanches. Natural and rider-triggered activity on this layer has died down over the past week but in the neighboring central Columbia region, where it is buried deeper, this layer continues to produce rider-triggered avalanches up to size 2.5. Cold temperatures and little snowfall are not likely going to help heal this layer.

Snowpack Summary

Up to 15 cm overlies variable surfaces ranging from hard old wind slabs in exposed features at upper elevations to soft, unconsolidated facets in sheltered areas.

A concerning weak layer composed of surface hoar, facets, and/or a crust that formed in mid-November is now buried 40 to 80 cm deep. Avalanche activity on this layer has tapered off but it is likely still possible to trigger this layer in isolated terrain features at treeline.

Alpine snowpack distribution is variable, with depths ranging from 70 to 140 cm.

Terrain and Travel Advice

  • Avoid open slopes and convex rolls at and below treeline where weak layers may be preserved.
  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.

Regioni coperte