Avalanche Forecast

Issued: Apr 19th, 2023 4:00PM

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

Avalanche Canada lbaker, Avalanche Canada

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Dangerous avalanche conditions exist in the alpine where 20-40 cm of storm snow and northwesterly winds are building fresh storm slabs. Use caution in wind loaded areas where storm slabs are deeper, more cohesive, and are most likley to be reactive to human triggering.

Summary

Confidence

Moderate

Avalanche Summary

On Tuesday, a widespread natural dry loose avalanche cycle was observed, up to size 1.5. Avalanches primarily initiated in steep alpine terrain.

If you have any observations from this region, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

In the alpine and at treeline, 20-40 cm of storm snow is rapidly settling with daytime warming. Down 20-50 cm a thick melt freeze crust is found up to 2200 m.

The mid snowpack is generally settled and strong at treeline and above.

A weak layer of large, sugary crystals persists at the base of the snowpack. This layer has not produced recent avalanche activity in this area, but professionals continue to monitor for signs of it becoming active.

Weather Summary

Wednesday Night

Cloudy with isolated flurries, 3 cm accumulation. Light northwest ridgetop winds. Freezing levels 1400 m. Treeline low around -6 °C.

Thursday

Mainly cloudy with isolated flurries, trace accumulations. Light northwest ridgetop wind. Freezing levels 1800 m. Treeline high around -1 °C.

Friday

Mix of sun and cloud with isolated flurries, trace accumulations. Light west ridgetop wind. Freezing levels rise from valley bottom to 1900 m by mid-day. Treeline high 0 °C.

Saturday

Mostly cloudy with sunny periods and isolated flurries, trace accumulations. Moderate west ridgetop wind. Freezing levels rise from valley bottom to 2100 m by mid-day. Treeline high +1 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Brief periods of sun could quickly initiate natural avalanche activity.
  • Be especially cautious as you transition into wind affected terrain.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

20-40 cm of storm snow and warm temperatures have formed cohesive slabs at higher elevations. Slabs are likely most reactive to human triggering on lee slopes where northwest winds have built deeper pockets of slab.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Loose Dry

An icon showing Loose Dry

Be alert to changing conditions when daytime heating and direct sun are impacting slopes. Rocks will heat up with daytime warming and may become trigger points for loose avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 20th, 2023 4:00PM

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