Avalanche Forecast

Issued: Apr 18th, 2023 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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Use caution entering lee terrain features, as wind slabs may linger. Small avalanches could step down to a buried layer and form large avalanches.

Summary

Confidence

Moderate

Avalanche Summary

We haven't received any recent reports of avalanche observations. The most recent avalanches occurred about a week ago on the facet layer described in the Snowpack Summary (e.g., this MIN).

Snowpack Summary

Around 10 to 20 cm of snow fell over the past couple days with strong southerly wind, which may have formed wind slabs in lee terrain features. The snow may not bond well to underlying layers, including faceted snow in shaded aspects at high elevations or a hard melt-freeze crust on sun-exposed slopes and on all aspects below 1700 m.

A layer of facets and a crust from early April is buried up to 60 cm at treeline and alpine elevations.

The base of the snowpack remains faceted and weak. We haven't received any notes of recent avalanche activity on this layer, but the concern remains for steep and rocky slopes with a thin snowpack.

Weather Summary

Tuesday Night

Mostly cloudy with no precipitation, 20 km/h south wind, treeline temperature -6 °C.

Wednesday

Early morning sun then cloudy skies with isolated flurries, accumulation 1 to 3 cm, 10 km/h south wind, treeline temperature -4 °C, freezing level 1400 m.

Thursday

Cloudy skies with no precipitation, 10 km/h south wind, treeline temperature -4 °C, freezing level 1500 m.

Friday

Cloudy with snowfall, accumulation 1 to 3 cm, 20 to 30 km/h southwest wind, treeline temperature -3 °C, freezing level 1600 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Approach lee and cross-loaded slopes with caution.
  • Use ridges or ribs to avoid areas of wind loaded snow.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs may remain in lee terrain features from recent snow and strong southwest wind. Small avalanches could step down to a layer of facets and a crust buried 60 cm that could result in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

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