Bollettino valanghe

Kootenay Boundary

Mar 6 – 7, 2015Avalanche Canada
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Archiviato · scaduto 12 years ago

Pericolo valanghe

Sun
Mon
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole

In sintesi

Warm air temperatures with strong afternoon sun may destabilize the upper snowpack on south-facing slopes. Use extra caution on sun exposed slopes during the afternoon.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    Light snowfall on Monday and ongoing moderate winds from the N through W directions have created pockets of thin wind slabs in leeward terrain features. Afternoon sun and warming may increase the sensitivity of triggering these wind slabs.
  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    Warming temperatures and solar radiation may cause sluffing on steep sun exposed slopes in the afternoon.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

The ridge of high pressure continues to keep things dry and clear for the next 3 days. On Saturday, mostly sunny conditions are expected with light NW winds in the alpine. Freezing levels are expected to be around 2000m. On Sunday and Monday, mainly sunny conditions are expected to continue with light winds from the W-NW and freezing levels staying around 2000m.

Avalanche Summary

On Tuesday and Wednesday there were reports of small wind slabs being triggered by skiers and explosives. Also, natural sun-triggered sluffing of the new snow was reported from steep sun-exposed slopes. As it warms and the amount of sun increases on Saturday, it may become easier to trigger the thin old pockets of wind slabs.  During the afternoon it may be possible to trigger sluffing from steep sun-exposed slopes.

Snowpack Summary

Shady and sheltered slopes have 5-15 cm of recent new snow. Ongoing outflow winds have redistributed this new snow in wind-exposed terrain resulting in a highly variable snow surface and the formation of thin wind slabs in leeward features. Steep sun-exposed slopes have a thin new sun crust on the surface. The most prominent feature in the snowpack is the thick late-Feb crust, down 5-30 cm. This crust is supportive all the way to ridge crest and is effectively "capping" the snowpack, keeping riders from stressing any deeper weak layers. There are still weak layers below this crust that we'll continue to monitor, but for now these layers are dormant. We would likely need significant warming and/or heavy loading to re-activate them.

Regioni coperte