Bollettino valanghe

Northwest Coastal

Jan 24 – 25, 2016Avalanche Canada
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Archiviato · scaduto 11 years ago

Pericolo valanghe

Tue
Wed
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato

In sintesi

Monday could be the calm before the storm(s). Regardless, it is still a day to exercise constraint and conservative decision-making.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–4
    Storm and wind slabs continue to grow. These slabs may be particularly touchy in exposed lee (W-NE) and cross-loaded terrain. 
  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–5
    Buried surface hoar, now 60 cm deep on average, is primed for triggering. It's possible for light loads to trigger slabs even from relatively low angle slopes. Be extra cautious near treeline where surface hoar is more likely to be preserved. 

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Monday: Mainly cloudy with light snow – 2-5 cm. The freezing level is around 1000-1400 m. Winds are moderate or strong from the S-SW. Tuesday: Periods of snow or rain – 10-20 mm/cm. The freezing level climbs to 1200-1500 m and winds remain strong. Wednesday: More rain or snow – possibly very heavy. The freezing level could jump to 2000 m and winds will keep blasting from the South.

Avalanche Summary

Explosives control on Saturday produced numerous slab avalanches up to size 3. Most of these failed on the mid-January surface hoar and some stepped down to the Boxing Day surface hoar layer. One observer also viewed numerous size 3 natural slabs on a variety of aspects, but these may have been a day or two old.

Snowpack Summary

Light snowfall and steady moderate S-SE winds continue. Expect fresh wind slabs overlying older wind-affected surfaces in exposed lee and cross-loaded terrain. The January 9th surface hoar/facet layer down 60-80 cm in most places, and seems most concerning at and below treeline. Recent snowpack tests give moderate "pops" results on this layer. Approximately 10 cm below this weakness you might find the Dec. 26/31 surface hoar layer. Reports of remote triggering, whumpfing, and sudden shears in snowpack tests are all indications that both these layers could propagate well if triggered. Deeper persistent weaknesses buried in December have the potential to wake-up to heavy loading, rapid warming, or avalanches stepping-down.

Regioni coperte