Bollettino valanghe

Kootenay Boundary

Feb 9 – 10, 2020Avalanche Canada
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Archiviato · scaduto 7 years ago

Pericolo valanghe

Tue
Wed
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole

In sintesi

Enjoy glimpses of the sun! Wind direction shifted from southwest to northwest and back again. Watch out for wind slabs on all aspects when transitioning into wind affected terrain. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Wind has recently switched direction from southwest to northwest and back again. Most of the recent avalanches released within the recent storm snow. Wind slabs might still be sensitive to human triggers especially when they get hit by the sun.

Confidence

High -

Weather Forecast

Saturday Night: Flurries, accumulation up to 5 cm, light northerly wind, alpine high -6 C, freezing level at valley bottom.

Sunday: Mix of sun and cloud, moderate northwest wind, alpine high -8 C, freezing level 800 m.

Monday: Mostly sunny, light to moderate northerly wind, alpine high -9 C, freezing level 900 m.

Tuesday: Mix of sun and cloud, light southwest wind, alpine high -6 C, freezing level 900 m.

Avalanche Summary

On Friday a few small (size 1) slab avalanches were triggered by skiers in lee terrain features. 

On Thursday a few large (size 2-2.5) slab avalanches released naturally during the night. One large (size 3) slab avalanche was triggered by explosives in the west of the region. Several small (size 1-1.5) slab avalanches were triggered by skiers mainly on south and east aspects. 

On Wednesday several small (size 1) slab avalanches in the alpine were triggered by skiers. Several small (size 1) natural and skier triggered loose dry avalanches were reported in steep terrain at treeline and in the alpine. 

Snowpack Summary

Wind switching directions has redistributed recent new snow onto a variety of aspects. The snow surface varies from low density in wind sheltered areas to wind slab. Specific terrain features at treeline and in the alpine were scoured to a crust from early February before this last storm hit the region. As high as 2000 m, the upper snowpack contains a crust from recent warming and rain events. Generally the recent storm snow seems to bond well with the crust below. Several avalanches were observed to release within the recent storm snow. However, some avalanches slid on the crust below. 

Weak facet/crust layers near the base of the snowpack are particularly noteworthy in the western Boundary area.

Terrain and Travel

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Carefully evaluate steep lines for wind slabs.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.

Regioni coperte