Bollettino valanghe

Lizard-Flathead

Jan 19 – 20, 2023Avalanche Canada
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Archiviato · scaduto 4 years ago

Pericolo valanghe

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

In sintesi

Keep an eye on recent wind loading patterns to avoid newly formed wind slabs. A weak basal snowpack structure continues to demand diligent group management. Regroup in safe locations, space out, and avoid shallow rocky start zones.

Problemi valanghivi

  • Wind Slabs

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

    Reactive wind slabs exist at treeline and above.

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    2–3

    Weak, faceted grains make up the basal snowpack. Where supportive to riders, a melt-freeze crust may be providing a bridging effect, making it more difficult to trigger deeper layers. Any avalanche triggered this deep will likely be large and destructive. Be especially suspicious of shallow, rocky, or cross-loaded areas with variable snow depths.

Confidence

Moderate

Avalanche Summary

On Tuesday, human-triggered wind slabs up to size 1 were reported from treeline and above.

Ski cutting in the Fernie area on Monday yielded small (size 1) wind slab releases after the area received 15 cm of new snow. Natural dry loose releases from steep alpine terrain reached size 1.5.

Snowpack Summary

Up to 15 cm of recent snow now settles on wind-affected surfaces above 2000 m and on a crust below 2000 metres.

A crust/facet layer is down 50-90 cm (and 2-15 cm thick at TL elevation). Where it's thickest, it caps a well-settled and consolidated mid-snowpack.

Another crust/facet layer is down 70-150 cm. Below this crust, the basal snowpack is weak and faceted.

Weather Summary

Wednesday Night

Mainly cloudy with isolated flurries 5-10 cm. Ridge winds moderate to strong from the southwest. Freezing level 1000 m.

Thursday

Cloudy with isolated flurries in the morning and sunny periods developing in the afternoon. Moderate southwest winds, potentially strong in the alpine, increasing over the day. Treeline high temperature near -5.

Friday

Cloudy with sunny breaks. Ridge wind light from the West. Alpine temperatures near -8 and freezing levels valley bottom.

Saturday

Mostly cloudy with scattered flurries. Ridge wind moderate from the southwest and freezing levels valley bottom.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Regioni coperte