Avalanche forecast

Sea To Sky

Feb 28 – Mar 1, 2025Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Persistent weak layers are scary and will be more concerning in warm weather.

Rider-triggered avalanches are likely and could be very destructive.

Be mindful of overhead hazards.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2

    Reactive wind slabs will be sensitive to rider triggers in lee terrain near ridge tops and on cross-loaded features. At higher elevations, these slabs have the potential to step down to deeper layers and produce large avalanches.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–3

    Persistent weak layers have become active with increased load and warm temperatures. A small avalanche may also step down to produce larger avalanches. Avoid shallow areas where triggering slabs are more likely.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–1.5

    Periods of sunshine, where they emerge, will destabilize the surface snow on sun-exposed slopes. Loose avalanches may run naturally or with a human trigger.

Confidence

Moderate

Avalanche Summary

Natural avalanches (wind slab and persistent slabs) have been observed since Sunday up to size 3 from 2000 m and above.

Scary large avalanches (size 2.5) were remotely triggered by skiers and snowmobilers on northerly alpine and treeline slopes. They were triggered 100 to 400 m away and failed on a preserved surface hoar layer, down 80 to 100 cm. Professionals are concerned about this layer.

Snowpack Summary

Up to 60 to 80 cm of settling recent snow covers weak surfaces from mid-February, including faceted snow or large surface hoar crystal in sheltered terrain.

A thin sun crust is visible up to 2000 m on southerly slopes, while extensive strong southerly winds have redistributed recent snow and scoured exposed areas.

A weak layer, buried at the end of January, is now 80 to 120 cm deep in the snowpack. This may present as a crust on sunny slopes, sugary facets in most places, and surface hoar in sheltered spots. Natural avalanches, large human triggering and several remote triggering have been continually reported on this concerning weak layer since Sunday.

Weather Summary

Thursday Night

Cloudy. 20 to 30 km/h southwesterly ridgetop wind. Treeline temperature +0°C. Freezing level reaching 2200 m.

Friday

Mix of sun and clouds. 10 to 20 km/h south ridgetop wind. Treeline temperature +5°C. Freezing level reaching 2800 m.

Saturday

Mix of sun and clouds. 30 to 50 km/h southeast ridgetop wind. Treeline temperature +3°C. Freezing level reaching 2500 m.

Sunday

Mostly cloudy. 10 to 20 km/h northeast ridgetop wind. Treeline temperature +0°C. Freezing level around 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be aware of the potential for large avalanches due to buried weak layers.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.
  • Cornices often break further back than expected; give them a wide berth when traveling on ridgetops.
  • Avoid exposure to overhead hazards when solar radiation is strong.

Regions covered