Avalanche Forecast
Issued: Apr 5th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
wlewis,
Avalanche Canada
Wind slabs remain the primary concern as light snowfall and strong wind continues. Watch for wind slabs around ridgelines and in mid slope terrain features in areas that see stronger winds.
Summary
Confidence
Avalanche Summary
Reactive wind slabs were reported on Sunday at alpine elevations in north facing terrain.
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 to have failed on a layer of facets above a crust buried in January.
Let us know what you are seeing by submitting a report to the Mountain Information Network.
Snowpack Summary
Gradual accumulations of fresh snowfall will 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.
A weak layer of surface hoar/crust/facets buried in early January is now 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.
Weather Summary
Wednesday Night
Cloudy with up to 5 cm. Moderate to strong southerly winds. Freezing levels drop to 500 m.
Thursday
Cloudy with up to 5 cm. Moderate to strong southerly winds. Freezing levels around 1200 m.
Friday
Mostly cloudy with trace amounts of snowfall. Moderate southerly winds. Freezing levels remain below 1000 m.
Saturday
Light snowfall returns with strong to extreme southerly winds. Freezing levels around 1000 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
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
Expected Size
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
Expected Size
Valid until: Apr 6th, 2023 4:00PM
