Avalanche Forecast

Issued: Apr 18th, 2023 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Loose Wet.

Avalanche Canada mconlan, Avalanche Canada

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Stormy conditions continue, which warrants conservative terrain travel.

Summary

Confidence

Moderate

Avalanche Summary

Recent storm snow was reactive to human traffic during Tuesday's stormy weather (e.g., as seen here). We also suspect that a natural avalanche cycle may have occurred out of steep terrain features.

Looking to Wednesday, we expect that natural avalanche activity will subside but that riders could trigger similar avalanches as the storm continues.

Snowpack Summary

The region has seen upwards of 100 cm of snow since the weekend, with another 20 to 30 cm forecast by Wednesday afternoon. All of this snow overlies a hard melt-freeze crust up to at least 1000 m and to ridgetop on sun-exposed slopes and perhaps small surface hoar crystals on shaded slopes sheltered from the wind.

The remainder of the snowpack is well-bonded.

Cornices are large and looming and continue to grow during this stormy weather.

Weather Summary

Tuesday Night

Cloudy with snowfall, accumulation 5 to 10 cm, 30 to 40 km/h southeast wind, treeline temperature -3 °C, freezing level 800 m.

Wednesday

Cloudy with snowfall and late-afternoon clearing, accumulation 15 to 30 cm, 20 to 30 km/h southeast wind, treeline temperature -2 °C, freezing level 1000 m.

Thursday

Mix of sun and cloud with isolated flurries, accumulation 2 to 5 cm, 10 km/h southeast wind, treeline temperature -1 °C, freezing level 1100 m.

Friday

Cloudy with snowfall, accumulation 5 to 10 cm, 20 to 40 km/h south wind, treeline temperature 0 °C, freezing level 1200 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
  • Choose relatively conservative lines and watch for clues of instability.
  • Avoid terrain traps where the consequence of any avalanche could be serious.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Storm Slabs

An icon showing Storm Slabs

Substantial snow accumulation has formed storm slabs that could be triggered by riders. Dial back your terrain choices to give the snow time to settle and bond to the snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Loose Wet

An icon showing Loose Wet

Rain at lower elevations will increase the likelihood of wet loose activity. The most problematic elevations are likely near the freezing level, where snow accumulates and is then soaked by rain.

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Apr 19th, 2023 4:00PM

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