Avalanche Forecast

Issued: Mar 4th, 2023 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is below threshold. Known problems include Wind Slabs and Persistent Slabs.

Avalanche Canada dnylen, Avalanche Canada

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Be suspicious of areas where the wind is actively depositing snow.

Strong wind can make windslabs in less common areas, like part way down large slopes, and on steep cut banks.

Summary

Confidence

Moderate

Avalanche Summary

A natural avalanche cycle up to size 3 has been observed from the highway in the inland areas around Paddy peak. We suspect that some of these may include step-downs to buried weak layers.

On Friday, our field team also observed new windslab avalanches up to size 2 and loose snow sluffing from steep alpine terrain around the White Pass.

Snowpack Summary

Recent snow has been stiffened at the surface in exposed areas and transported into wind slabs by strong outflow wind at all exposed elevations.

The mid snowpack is generally hard with a couple of crusts buried 60+ cm and 100+ cm deep, these have been problematic on north to east aspects as high as 1700 m, where they are covered in an overlying layer of weak surface hoar crystals. In inland areas these weak layers are closer to the surface and are easier to trigger.

At the base of the snowpack large sugary crystals persist.

Weather Summary

Saturday night

Possible flurries. Moderate to strong northeasterly wind. -20 ºC.

Sunday

Sunny. Moderate to strong northeasterly wind. Alpine temperature -16 ºC.

Monday

Mostly cloudy. Snow beginning in the afternoon, up to 5 cm. Strong northerly wind. Inversion, alpine high -10 ºC.

Tuesday

Mostly sunny. Strong northerly outflow wind. Alpine high -15 ºC.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Seek out sheltered terrain where new snow hasn't been wind-affected.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong northerly winds will be transporting snow into reactive wind slabs in all exposed terrain especially near ridge crests and sharp breaks in terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A weak layer of surface hoar and/or facets buried ~100 cm deep has produced occasional large, widely propagating avalanches on north to east aspects above 1500 m. Some avalanches have been remotely triggered from hundreds of meters away! A layer at this depth may not show obvious signs of instability. Best to avoid steep or unsupported high consequence alpine terrain.

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

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Mar 5th, 2023 4:00PM