Bulletin d’avalanche

South Rockies

Apr 18 – 19, 2023Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

Thu
Fri
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Points saillants

Dial back your terrain choices where you are finding more than 20 cm of new snow. Avoid wind loaded areas where slabs are deeper, more cohesive, and are likely reactive to human triggering.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2

    The Elkford area is forecast to get the highest snowfall amounts with up to 20 cm.

    Strom slabs will be reactive in areas that receive higher snowfall amounts and on steep, wind exposed slopes where new snow is more likely to form a cohesive slab. Use caution around leeward terrain features where deposits are deep.

    In southerly facing terrain expect new snow to overlay a melt freeze crust, providing an ideal sliding surface for storm slabs.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–4

    The base of the snowpack remains weak. Avoid thin, rocky start zones and shallow areas with variable snowpack depths.

Confidence

Low

Avalanche Summary

No new avalanches were reported in this region on Monday.

We expect backcountry users will see evidence of a large avalanche cycle from last week's rain event when numerous wet loose avalanches reached the valley bottom.

If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

In the alpine and around treeline, 20-40 cm of snow covers a frozen crust.

The mid snowpack is generally settled and strong, except in areas with snow depths less than 150 cm. In these lower snow areas, the mid-pack is likely weaker and more faceted.

The lower snowpack includes a layer of large, weak facets and/or depth hoar crystals.

Below treeline, expect to find moist or refrozen surfaces, and a shrinking snowpack that is isothermal during the heat of the day.

Weather Summary

Tuesday Night

Cloudy with scattered flurries. 3-9 cm of snow is expected in the alpine. Light northerly ridgetop wind. Freezing levels fall to 1000 m. Treeline high around -5 °C

Wednesday

The Elkford region is forecast to be cloudy with scattered flurries, 10-20 cm of new snow in the alpine.

In the Purcells and Bull area, 2-3 cm of new snow is forecast.

Both regions will see light northwest ridgetop wind. Freezing levels of 1500 m and treeline highs around -1 °C.

Thursday

Mainly cloudy with sunny periods and isolated flurries, trace accumulations. Light west ridgetop wind. Freezing level at 1700 m. Treeline high around -1 °C.

Friday

Mainly sunny with cloudy periods. Light southwest ridgetop wind. Freezing level at 2000 m. Treeline high around 0 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for changing conditions today, storm slabs may become increasingly reactive.
  • Be carefull around freshly wind loaded features.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.

Régions couvertes