Bollettino valanghe

Sea To Sky

Feb 4 – 5, 2020Avalanche Canada
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Archiviato · scaduto 7 years ago

Pericolo valanghe

Thu
Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole

In sintesi

Carefully evaluate terrain for overhead cornice hazard and areas where wind slabs may remain reactive to human triggering.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2.5

    Wind changing in direction from southwest to northwest has loaded new features which may be sensitive to human triggering.

  • Cornices

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

    Significant cornice growth has been observed. Recent natural and explosive triggered cornices have produced large avalanches (size 2-3). Avoid overhead cornice hazard and stay well back from lee side of ridges.

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Monday Night: Mainly clear. Light north wind. Alpine high -10 C.

Tuesday: Flurries, accumulation 5-10 cm. Moderate southwest wind. Alpine high -6 C.

Wednesday: Flurries, accumulation 5-15 cm overnight Tuesday night into Wednesday and an additional 5 cm through Wednesday. Moderate to strong west wind. Alpine high -2 C. Freezing level 1000 m.

Thursday: Flurries, accumulation 10-15 cm. Light moderate west wind, Alpine high -2 C. Freezing level 1000 m. 

Avalanche Summary

On Sunday there were reports of explosives controlled wind slab and storm slab avalanches to size 2 in the alpine. There was also a report of a size 3.5 naturally triggered deep persistent avalanche on a northwest aspect at 2600m. This would have run during or just after the storm on the weekend.

On Saturday, a widespread natural cycle and extensive explosive work produced cornice and storm slab avalanches size 2-3.

Additionally, natural and explosive triggered deep persistent slab avalanches size 3-4 have been reported in the Lillooet River valley north of Pemberton, at the eastern border of the region.

Snowpack Summary

Extreme southwest wind leading into last weekend has scoured windward aspects, formed loaded pockets up to 150 cm deep in alpine lees and contributed to rapid cornice growth. Below 1900 m, recent snow overlies a thick crust and tapers quickly with elevation.

Weak faceted grains and crusts near the base of the snowpack have not been an active avalanche problem recently, despite significant new snow loads. They are still on our radar, especially in inland parts of the region.

Terrain and Travel

  • Carefully evaluate bigger terrain features on an individual basis before committing to them.
  • Extra caution is needed around cornices under the current conditions.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.

Regioni coperte