Avalanche Forecast

Issued: Apr 17th, 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.

Avalanche Canada jsmith, Avalanche Canada

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Forecast snow and light to moderate northeast wind Monday night may form fresh wind slabs on lee features.

Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Summary

Confidence

Low

Avalanche Summary

A naturally triggered large wind slab avalanche was reported on a north facing slope in the alpine on Sunday. See MIN

A size 3 persistent slab avalanche was reported on a southeast aspect in the alpine west of Kelsall lake on Thursday. It was suspected to have been triggered by solar radiation.

Observations are limited at this time of year, please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.

Snowpack Summary

20-30 cm of recent snow and light to moderate south wind may have formed wind slabs in isolated lee features in the alpine.

The recent snow sits over previously wind-affected snow surfaces on northerly aspects and sun crust on other aspects.

A weak layer of surface hoar/crust/facets buried in early January is now around 100 cm down in most areas. Operators continue to monitor this layer. A significant warming event or a large trigger (like a falling cornice) are the most likely things to activate this layer.

Weather Summary

Monday Night

Snow; 10-15 cm / 20 km/h northeast ridgetop wind / Temperature at treeline around -7 C / Freezing level valley bottom

Tuesday

Cloudy with flurries; 5-10 cm, then another 5-15 cm overnight / 30 km/h east ridgetop wind / Temperature at treeline around -2 C / Freezing level 1200 m

Wednesday

Mix of sun and cloud / 30 km/h east ridgetop wind / Temperature at treeline around -2 C / Freezing level 1300 m

Thursday

Mix of sun and cloud with isolated flurries; 0-3 cm / 30 km/h northeast ridgetop wind / Temperature at treeline around -4 C / Freezing level 1100 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.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Cornice failure may trigger large avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Forecast snow and light to moderate northeast wind Monday night may form fresh wind slabs on lee features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

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

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