Bollettino valanghe

Sea To Sky

Nov 28 – 29, 2012Avalanche Canada
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Archiviato · scaduto 14 years ago

Pericolo valanghe

Fri
Sat
Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Apri la mappa completa

In sintesi

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    1–4
    Heavy amounts of new snow will build storm slabs on all aspects, overlying a variety of weak surface layers. Storm slabs, and new wind slabs will be touchy, and widespread natural avalanche activity is likely with heavy loading from snow and wind.

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–6
    Slopes with smooth ground cover and reloaded bed surfaces. Prone to remote triggering and step down avalanches. Typical trigger points include thin rocky areas. May be difficult to trigger, but often very large with serious consequences.

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

A deep low pressure system off the Gulf of Alaska will be bringing a very moist, warm and active weather pattern over the next five days. The system will move into the region Wednesday afternoon, and persist with moderate to heavy amounts of precipitation through the weekend. Thursday: FLVL’s 1500 m, snow amounts up to 30 cm, ridegtop winds SE 40-gusting 70 km/hr, alpine temps -2.0.Friday: FLVL’s 1400 m, snow amounts 15-25 cm, ridgetop winds SE 60-gusting 90 km/hr, alpine temps -3.0.Saturday: FLVL’s 1400 m falling 1000 m overnight, snow amounts heavy, ridgetop winds S 20 kn/hr, alpine temps -3.0.

Avalanche Summary

No new observations today. Reports from the Whistler area on Tuesday include a Size 2.5 deep slab avalanche running on the early November facet/crust combo triggered with small explosives low on the slope. Check out Wayne Flann's Avalanche Blog for more information, including photos. Also of note, there was a report of a size 2.5 skier triggered avalanche on Saturday. This avalanche occurred on a northeast aspect in the alpine. It was triggered from the bottom of the slope, and likely released on the early November layer. Widespread natural avalanche activity will be the theme over the forecast period.

Snowpack Summary

The region will see heavy amounts of new snow, and strong winds. Storm slabs will load a variety of weak surfaces. These surfaces consist of large surface hoar, a thin sun crust, surface facets, moist snow, or preserved storm snow depending on elevation, sun and wind exposure, slope angle, time of day, and aspect. A storm snow instability has been noted down 30 cm, giving consistent moderate "pops" results in snowpack tests. Snowpack tests continue to show sudden collapse (or "drops") results on the early November facet/crust deep persistent weakness, but because this weakness is so close to the ground in most areas, associated avalanche activity will likely be limited to slopes with smooth ground cover (e.g. scree slopes, rock slabs, summer firn, glaciers, etc.).

Regioni coperte