Avalanche Forecast

Issued: Apr 17th, 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 lbaker, Avalanche Canada

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Human-triggered avalanches are possible in wind loaded areas at alpine and treeline. Be cautious when transitioning into wind-affected features.

Expect variable snowpack conditions as we transition from winter to spring.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches were reported before 4 pm on Monday.

On Sunday, near Fernie, a large (size 2) avalanche on a northwest aspect at approx. 2000 m was initiated during daytime warming and direct solar influence. Small (size 1) natural wet loose avalanche activity continues to be reported in steep treeline features.

If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

Dynamic spring weather has resulted in variable snow surface conditions. A wet storm last week soaked the upper snowpack. Cold overnight temperatures have turned this moist snow into a frozen crust, except in areas where dry snow covered and insulated it.

The mid snowpack is generally settled and strong, except in areas with snow depths less than 150 cm. In these lower snow areas, the mid-pack is likely weaker and more faceted.

Below treeline, expect to find moist or refrozen surfaces, and a shrinking snowpack that is isothermal during the heat of the day.

The lower snowpack includes a layer of weak sugary crystals near the ground. This layer has shown signs of gaining strength, and it has not produced recent avalanche activity in this area.

Weather Summary

Monday Night

Scattered cloud. Light southeast ridgetop wind. Freezing levels drop to 1000 m in most areas overnight. Treeline low -5°C.

Tuesday

Cloud increasing through the morning. Afternoon flurries bring 10 cm of new snow to the alpine. West ridgetop winds increase from light to moderate in the afternoon. Freezing level 1600 m. Treeline high 0 °C.

Overnight flurries continue, an additional 5-10 cm of snow is expected.

Wednesday

Mix of sun and cloud with isolated flurries, trace accumulation. Moderate west ridgetop wind. Freezing level 1600 m. Treeline high around 0 °C.

Thursday

Cloudy with scattered flurries, 5-10 cm of snow is expected in the alpine. Moderate northwest ridgetop wind. Freezing level 1600 m. Treeline high around 0 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be alert to conditions that change throughout the day.
  • Stay off recently wind loaded slopes until they have had a chance to stabilize.
  • Be carefull around freshly wind loaded features.
  • Watch for unstable snow on specific terrain features, especially when the snow is moist or wet.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong west winds are redistributing 5-10 cm of new snow into pockets of fresh wind slabs in alpine and treeline lees. Expect this problem to become sensitive to light triggers, once the temps rise. Human triggering remains possible on steep wind-loaded features.

Carefully evaluate for windslab hazard before committing to bigger features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 18th, 2023 4:00PM