Avalanche Forecast

Issued: Feb 26th, 2023 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Avoid avalanche terrain during periods of strong sun or warm temperatures. Human-triggered storm slabs remain LIKELY. Continue choosing low-angle, low-consequence terrain.

Summary

Confidence

Moderate

Avalanche Summary

Last week, northerly outflow winds created small (size 1) but reactive wind slabs at ridge crests.

On Sunday, a widespread natural cycle is suspected to have occurred throughout the region. Reports came in of very touchy human-triggered storm slabs averaging 50 cm deep and up to 100 cm deep in wind-loaded areas.

Looking forward to Monday, dangerous avalanche conditions will persist. Expect natural and human-triggered storm slabs to be likely, especially in wind-loaded areas and on sun-exposed slopes.

Check out Friday's North Shore Snowpack Update for a picture of the unusual snowpack setup leading into Sunday's storm.

Snowpack Summary

Saturday night's storm brought 30-50 cm of new snow down to valley bottom. This new snow has bonded poorly to the underlying surface formed by recent wind and cold temperatures. This surface consists of weak faceted snow, old hard wind slabs and a breakable crust between 1100 and 1600 m.

The mid and lower snowpack is well-settled, strong, and consolidated.

Snowpack depths are reaching 250 cm at treeline.

Weather Summary

Sunday night

Clear periods with isolated flurries, up to 5 cm of accumulation. Alpine temperatures drop to a low of -7 °C. Ridge wind south 15 to 20 km/h. Freezing level 100 metres.

Monday

A mix of sun and cloud with isolated flurries. Alpine temperatures reach a high of -4 °C. Ridge wind east 10-25 km/h. Freezing level 700 metres.

Tuesday

A mix of sun and cloud. Alpine temperatures reach a high of -4 °C. Ridge wind northwest 10 km/h. Freezing level 500 metres.

Wednesday

Cloudy with sunny periods. Alpine temperatures reach a high of -6 °C. Ridge wind light from the southwest. Freezing level 200 metres.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Give the new snow several days to settle and stabilize before pushing into bigger terrain.
  • Stick to simple terrain or small features with limited consequence.
  • Avoid being on or under sun exposed slopes.
  • Avoid terrain traps where the consequence of any avalanche could be serious.
  • Don't let the desire for deep powder pull you into high consequence terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

Saturday night's storm brought 50 cm of storm snow that has bonded poorly to the underlying surface. This has created a widespread storm slab problem with deeper and more reactive deposits observed in wind-loaded areas.

Even brief periods of sun could cause rapid settlement in the storm snow and initial natural avalanches. Avoid being on or under sun-exposed slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Loose Dry

An icon showing Loose Dry

In steeper areas where the storm snow has not formed a cohesive slab, touchy dry loose avalanches will be widespread.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely - Certain

Expected Size

1 - 2

Valid until: Feb 27th, 2023 4:00PM