Bollettino valanghe

Vancouver Island

Dec 27 – 28, 2021Avalanche Canada
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Archiviato · scaduto 5 years ago

Pericolo valanghe

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

In sintesi

As the wind picks up, fresh reactive wind slabs are likely to form at upper elevations. Great riding can still be found in sheltered, low elevation terrain thanks to the chilly temps!

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–2

    With plenty of soft, light snow available for wind transport, we expect to see wind slab formation at upper elevations (and possibly in open areas at lower elevations) as winds pick up on Monday. A northwesterly wind direction means atypical cross-loading and reverse loading patterns are likely.

Terrain and Travel

  • Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
  • Wind slabs are most reactive during their formation.
  • Avoid freshly wind loaded terrain features.
  • Sheltered slopes at lower elevations will offer the best riding.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

Sunday night: Clear. Light northwest wind. Treeline temperatures -18 C.

Monday: Increasing cloud with flurries starting. Wind increasing to strong northwest. Treeline temperatures around -13 C.

Tuesday: Flurries overnight then clearing. Strong northwest wind. Treeline temperatures around -10 C.

Wednesday: Increasing cloud. Strong northwest wind. Treeline temperatures around -8 C.

Avalanche Summary

No new reports of avalanche activity over the weekend. Avalanche activity on Thursday and Friday was predominantly small loose dry, size 1-1.5, observed out of steep terrain at treeline. On Thursday, evidence of natural storm slab avalanches size 2-2.5 were observed out of north facing alpine terrain.

Snowpack Summary

With plenty of soft, light snow available for wind transport, we expect to see wind slab formation at upper elevations as winds pick up on Monday. A northwesterly wind direction means atypical cross-loading and reverse loading patterns are likely.

20-40 cm now sits over a freezing rain crust below 1500 m and above this elevation it may rest on a layer of large surface hoar crystals. Our field team reported easy shears on this layer in their MIN report from during the storm on Wednesday but we're uncertain as to whether this layer remains a problem. You can see photos of the surface hoar prior to being buried by the storm in these MIN reports from Elk Mountain on Monday and Mt Kitchener on Tuesday.

A crust-facet sandwich formed in early December can now be found a meter deep. These layers show limited reactivity and are well bridged by strong snowpack layers above them. Below, the snowpack is generally well-settled.

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