Bollettino valanghe

Banff Yoho Kootenay

Apr 7 – 8, 2024Avalanche Canada
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Archiviato · scaduto 2 years ago

Pericolo valanghe

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

In sintesi

Start and finish early to enjoy the good travel and lower hazard. Monday should stay cooler, but watch for wet loose avalanches later in the day with daytime warming and solar inputs.

Moderate winds may form small windslabs in steep alpine terrain, and continue to use caution in steep northerly thin snowpack terrain in the alpine.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1–2

    The recent 15-25 cm has been distributed into some deeper and denser pockets by light variable winds. Ridgetop winds are forecast to increase into the moderate range from the SW on Monday, so we may see further slab development in high elevation lee areas.

  • Persistent Slabs

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

    The Feb 3 layer is down 60-120 cm. In shallow snowpack areas on northerly alpine aspects, this layer may still be sensitive to skiers, with remote triggering observed in a couple of instances last week. All recent avalanches that initiated on this Feb 3 layer stepped down to the basal facets/ground.

  • Loose Wet

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

    Solar inputs and daytime warming will result in moist surface snow on steep solar aspects and at lower elevations. If things warm up enough we may see wet loose avalanches in the afternoon. Remember that even a short burst of sun can develop moist snow very quickly on steep slopes.

Confidence

High

Avalanche Summary

No new avalanches were observed or reported on Sunday.

On Friday and Saturday multiple solar triggered loose wet avalanches up to size 1.5 were reported in steep solar terrain as the most recent storm snow heated up.

It has been a week since the last skier triggered avalanches on the Feb 3rd persistent weak layer occured. These involved a skier remote in Purple Bowl and a skier accidental at the Cathedral Glades.

Snowpack Summary

New surface crusts on all solar aspects and up to 2500 m on north aspects. On high north aspects 15-20 cm of recent storm snow remains dry with some wind effect near ridgecrests.

The February 3 persistent weak layer remains a concern for human triggering in shallow snowpack areas on northerly alpine aspects where no crusts are found in the upper snowpack and the midpack remains thin and weak.

Weather Summary

Monday: Moist southwest flow aloft will generate cloudy skies and flurries at higher elevations. Southwest ridgetop winds will range from 35 to 50 km/h.  

Precipitation will be mainly on the windward side of the Rockies but some snow will drift across to the eastern slopes through the afternoon. Freezing levels will be between 1800-2000 m.

Click here for more weather info.

Terrain and Travel Advice

  • Remember that in the spring strong solar radiation and warm temperatures can weaken the snow in a matter of minutes.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

Regioni coperte