Avalanche forecast

Sea To Sky

Mar 3 – 4, 2024Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable

Highlights

Despite reduced danger ratings and natural activity, dangerous avalanche conditions still exist

Stick to very conservative terrain, avoid exposure to large slopes or overhead hazard

Avalanche problems

  • Persistent Slabs

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

    Facets/surface hoar above a crust is most concerning at treeline elevations. Storm slab avalanches may step down to this layer resulting in very large, destructive avalanches.

    Use low-angle, simple terrain to help manage this problem.

  • Storm Slabs

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

    Deeper and more sensitive slabs exist on north and east facing slopes near ridges. Danger may rise quickly if the sun appears.

    Good travel habits are key, minimize your exposure to avalanche terrain and evaluate safe spots with caution.

Confidence

Moderate

Avalanche Summary

On Friday explosive control and riders triggered slabs up to size 2.5, 40-100 cm deep. Storm snow remains reactive to human triggers, check out this MIN for more details.

Numerous large, remotely triggered avalanches have occurred throughout this storm, most recently reported on Thursday to size 3.

Observations are limited as operators are very cautious about stepping into avalanche terrain. We expect natural activity has tapered but human triggering remains likely.

Snowpack Summary

Storm totals vary from 50-120 cm throughout the Sea to Sky corridor. Strong south/west winds have created deeper slabs on north and east facing slopes.

Multiple weak layers exist in the upper and mid snowpack. The most concerning layer is buried 50-120 cm deep, with a layer of facets (or in sheltered areas, preserved surface hoar) above a crust. This layer is likely most concerning at treeline.

This layer continues to be sensitive to human triggers, producing large and remotely triggered avalanches from low-angle terrain, indicating the need for cautious decision making. This snowpack will take time to begin to settle and bond, with the significant new load of storm snow adding stress to these weak layers.

Weather Summary

Saturday Night

Cloudy with flurries delivering up to 5 cm of snow. 20-30 km/h southerlywinds. Freezing level drops to sea level.

Sunday

Mostly cloudy with isolated flurries. 20-30 km/h southeast winds. Treeline temperature -7 °C. Freezing level around 800 m.

Monday

5-15 cm of snow is possible by Monday morning.

Cloudy with flurries in the morning with clearing skies and sunshine in the afternoon. 10-20 km/hr southwest winds. Treeline temperature -10 °C. Freezing level around 500 m.

Tuesday

Mostly clear skies. 30-40 km/h northwest winds. Treeline temperature -10 °C. Freezing level around 500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Remote triggering is a concern, avoid terrain where triggering slopes from below is possible
  • Brief periods of sun could quickly initiate natural avalanche activity.
  • Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.

Regions covered