Bollettino valanghe

Sea To Sky

Jan 27, 2018Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

Sun
Mon
Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato

In sintesi

New snow amounts within this region will be highly variable on Saturday with more snow in the south. Hazard may be one step lower in areas that receive less than 25 cm of new snow.

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2.5
    Large amounts of recent new snow and high winds are creating rapid cornice growth.
  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–2.5
    New snow, strong winds, and rising temperatures will create touchy storm slabs reactive to human triggers.
  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2.5–3.5
    Large triggers such as a falling cornice or smaller storm slab avalanches may step-down to deeply buried crusts, resulting in large and destructive avalanches running full path.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Saturday

Weather Forecast

SATURDAY: 20-30 cm of new snow / Strong southwesterly ridgetop winds / Freezing level rising to around 1000m.SUNDAY: 20-30 cm of new snow / Strong southwesterly ridgetop winds / Freezing level rapidly rising to around 1800m.SUNDAY NIGHT: 15-25 cm of new snow / Strong southwesterly ridgetop winds / Freezing level around 1800m.MONDAY: 25-30 cm of new snow / Strong to extreme southwesterly ridgetop winds / Freezing level around 1800m.

Avalanche Summary

Throughout this region there has been evidence of a natural avalanche cycle up to size 3 that occurred within the storm snow on Wednesday. More notable are the numerous explosive triggered, very large avalanches up to size 3.5 that where reported near Whistler on Thursday. These avalanches started in the storm snow and then stepped down to the early January and even the mid-December crusts which resulted in very large avalanches running full path. They occurred on northwesterly aspects below rocky ridgetops at around 1950 m. Although these layers are over 200 cm beneath the snow surface, a large trigger such as a falling cornice or a smaller human triggered avalanche could very likely "step-down" to these layers resulting in large and destructive avalanches.

Snowpack Summary

15-20 cm of new snow on Thursday morning brings recent storm totals to around 60-80 cm which continues to be redistributed by strong southeasterly winds. Last weekend's storm created dense storm slabs lurking in lee and cross-loaded features. Impressive cornice growth has also been observed on the lee side of ridgetops. 200-250 cm below the surface you'll find a crust that was buried early January and is present at all elevations. Below this there is another crust which was buried in mid-December. Recent explosive control work has triggered storm slab avalanches that have then "stepped-down" to both of these crusts, resulting in very large avalanches running full path. Although these layers are over 200 cm beneath the snow surface, a large trigger such as a falling cornice or a smaller human triggered avalanche could very likely "step-down" to these layers resulting in very large and destructive avalanches.

Regioni coperte