Avalanche forecast

Sea To Sky

Dec 16 – 17, 2024Avalanche Canada
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Avalanche danger

Wed
Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Carefully assess terrain and avoid areas below ridgelines with deep pillows of freshly loaded snow.

Stick to lower-angle terrain and reduce exposure to overhead hazard throughout the day.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1.5–2.5

    Wind slabs are certain to be present near ridge tops and where strong winds have loaded fresh snow onto leeward terrain features.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    Cooling temperatures and settlement will reduce the sensitivity to human triggering. In areas protected from the wind, surface hoar could be buried by the storm slab and this will increase the chance of an avalanche.

Confidence

Moderate

Avalanche Summary

Numerous avalanche reports from Saturday indicate activity across all aspects, primarily in treeline terrain, during the storm. Most avalanches were small storm slabs (size 1), but due to limited visibility, it is suspected that larger avalanches likely occurred in higher and more expansive terrain.

If you are going out in the backcountry, please consider sharing your observations to the Mountain Information Network (MIN).

Snowpack Summary

Storm snow amounts have average around 30 cm and in the most western reaches of the region exceed 50 cm. This new snow has accumulated on various surfaces, including surface hoar in wind-sheltered terrain at treeline and below, thin melt-freeze crust on south-facing alpine slopes, and old storm snow at higher elevations. Above 1200 m, a crust of concern is now estimated to be down 35 to 65 cm. The mid and lower snowpack is well-settled with no layers of concern.

Weather Summary

Sunday Night

Clearing. 10 to 15 km/h southeast ridgetop winds. Treeline temperature -4 °C. Freezing level 900 m.

Monday

Snow 5 to 10 cm . 20-40 km/h southeast ridgetop winds. Treeline temperature -6 °C. Freezing level 500 m

Tuesday

Snow flurries 1 to 5 cm. 30-60 km/h southwest ridgetop winds. Treeline temperature -3 °C. Freezing level 1000 m.

Wednesday

Snow and rain 30 to 70 mm. 60-80 km/h southwest ridgetop winds. Treeline temperature 0 °C. Freezing level 1700 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Keep your guard up at all elevations. Wind slab formation has been extensive and could extend into openings below treeline.
  • Use ridges or ribs to avoid areas of wind-loaded snow.
  • Expect slab conditions to change drastically as you move into wind-exposed terrain.

Regions covered