Avalanche Forecast

Issued: Apr 8th, 2023 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

Email

Watch for fresh and reactive wind slabs where new snow is available for transport.

Seek out low angle, sheltered terrain for the best turns.

Summary

Confidence

Moderate

Avalanche Summary

Warmer temperatures and some sun effect on Thursday produced small wet loose avalanches. Wind slabs were last reported earlier in the week, in north-facing terrain features.

On Friday a size 1 skier remote was reported on a north east facing slope at treeline. The avalanche was 40 cm deep and failed on a weak interface, possibly the mid-January layer. On Saturday a rider triggered a cornice fall from a distance, which produced a size 3 persistent slab avalanche on a northeast aspect at 1750 m. The avalanche was 200 cm deep and was suspected of having failed on the layer of facets above a crust buried in January.

Snowpack Summary

Around 25 cm of recent snowfall will continue to be redistributed by southerly winds into wind slabs over previously wind-affected snow on north and east facing slopes. South facing terrain will likely be stripped back to a crust by these winds. Lower elevations likely have a crust on or near the surface from recent warm temperatures.

A weak layer of surface hoar/crust/facets buried in early January is now buried over 1 m deep in most areas. This layer has produced recent avalanche activity and remains a concern in terrain where the snowpack is thin. The lower snowpack consists of basal facets, particularly in shallow areas.

Our field team travelled far and wide on Thursday, check our their MIN report here for current conditions.

Weather Summary

Saturday Night

Mostly cloudy with 5 cm of snow with strong southerly winds. Freezing levels drop to the valley bottom.

Sunday

Cloudy with 5 cm of snow with strong southerly winds. Freezing levels around 1000 m.

Monday

A mix of sun and cloud with moderate southwest winds. Freezing levels remain low around 500 m. Flurries are possible in isolated areas.

Tuesday

Mostly sunny with light southwest winds. Freezing levels remain around 500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Carefully evaluate steep lines for wind slabs.
  • Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.
  • 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 are present at higher elevations, in north and east facing terrain features. Small accumulations of fresh snow and continued winds may continue to build these slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A layer of facets sitting on a crust buried in January has recently been reactive. Triggering is most likely in areas where the snowpack is thin and weak, or with a heavy load like a cornice fall or the weight of a smaller avalanche in motion triggering this deeper layer.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 9th, 2023 4:00PM

Login