Avalanche Forecast

Issued: Mar 30th, 2023 4:00PM

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

Avalanche Canada shorton, Avalanche Canada

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

Summary

Confidence

Moderate

Avalanche Summary

Most avalanche activity this week has been limited to small (size 1) wet loose avalanches. Some natural cornice failures have been observed, but have not triggering slabs on slopes below.

However, a few outliers - large slab avalanches - have been reported throughout the region. Although we don't think we have a widespread problem, it's something to keep in mind as the spring warms up. On Monday, a size 2.5 wet slab was reported south of Terrace, originating from a steep and rocky start zone on a northwest aspect near treeline. On Tuesday, two large avalanches ranging from size 2.5-3 were observed in the alpine north of Stewart, possibly triggered by cornices and running on a weak layer buried in January that had previously not shown any signs of reactivity for several weeks.

Snowpack Summary

Up to 10 cm of new snow will fall on Friday with deeper deposits in lee terrain. In most areas this snow is falling on moist or crusty snow layers, except shaded terrain above roughly 1400 m where the snow has remained dry over the past week. The lower snowpack is strong and bonded.

Weather Summary

Thursday night

Increasing cloud, light flurries with 1 to 5 cm of snow, 40 km/h southwest wind, treeline temperatures around -5 °C with freezing level dropping to 500 m.

Friday

Cloudy, scattered flurries with 2 to 5 cm of snow (and some localized accumulations of 10 cm along the immediate coast), 50 km/h south wind, treeline temperatures around -3 °C with freezing level climbing to 800 m.

Saturday

Around 5 cm overnight then clearing to a mix of sun and cloud, 30 km/h southwest wind, treeline temperatures around -4 °C with freezing level climbing to 800 m.

Sunday

Sunny, no precipitation, 10 km/h northeast wind, treeline temperatures around -1 °C with freezing level climbing to 1100 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Carefully evaluate steep lines for wind slabs.
  • Avoid exposure to slopes that have cornices overhead.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Problems

Cornices

An icon showing Cornices

Beware of large cornices along ridgelines.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs

Small wind slabs could form in isolated alpine terrain throughout the day.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Mar 31st, 2023 4:00PM