Avalanche Forecast

Issued: Mar 31st, 2023 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Wind Slabs and Cornices.

Avalanche Canada shorton, Avalanche Canada

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Watch for cornices and new wind slabs if travelling into alpine terrain.

Summary

Confidence

Moderate

Avalanche Summary

We've seen a decline in avalanche activity over the past week, with most observers only seeing small (size 1) wet loose avalanches triggered by warm and sunny weather. Several large (size 2) cornice falls have been observed, most of which have not triggered slabs on the slopes below. However, there are a few exceptions where cornices did trigger large avalanches, including two avalanches north of Stewart on Tuesday (100 to 250 cm thick slabs) and one avalanche north of Terrace on Thursday (30 cm thick slab). This suggests that the snowpack is generally strong, but it could be possible for heavy triggers like a collapsing cornice to trigger a large avalanche.

Snowpack Summary

New snow amounts range from 5 to 20 cm, with deeper deposits in lee terrain. In most areas this snow has covered moist or crusty snow layers, except shaded terrain above roughly 1500 m where the snow has remained dry over the past week. The lower snowpack is strong and bonded.

Weather Summary

Friday night

Cloudy, light flurries with 1 to 5 cm of snow (and some localized accumulations of 10 cm along the immediate coast), 30 km/h southwest wind, treeline temperatures around -5 °C with freezing level dropping to valley bottom.

Saturday

Cloudy with sunny breaks in the afternoon, isolated flurries with 2 to 5 cm of snow, 20 km/h southwest wind, treeline temperatures around -5 °C with freezing level up to 800 m.

Sunday

Sunny, no precipitation, 10 km/h northwest wind, treeline temperatures around -3 °C.

Monday

Mix of sun and cloud, isolated flurries with trace amounts of snow, 20 km/h northwest wind, treeline temperatures around -3 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Carefully evaluate steep lines for wind slabs.
  • Caution around slopes that are exposed to cornices overhead.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs have likely formed in lee terrain and along ridges over the past few days. Since snowfall amounts have been relatively light, they are most likely small.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Cornices

An icon showing Cornices

Beware of cornices. There have been a few large cornice collapses the past few days, including some isolated cases where they've triggered slabs on the slope below. Be extra cautious on slopes below cornices.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1.5 - 2.5

Valid until: Apr 1st, 2023 4:00PM

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