Avalanche Forecast

Issued: Apr 13th, 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 jsmith, Avalanche Canada

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Lingering and reactive wind slabs remain at higher elevations.

Seek out terrain that has not been wind-affected.

Summary

Confidence

Moderate

Avalanche Summary

A naturally triggered size 2.5 wind slab was reported on a northeast aspect in the alpine on Wednesday. It failed at a depth of 40 cm on what is expected to be a melt-freeze crust that developed before our last storm.

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

20-40 cm of recent snowfall has been redistributed into wind slabs on north-to-east-facing terrain features by southwest winds. The recent snow sits over wind-affected surfaces or a crust on south-facing slopes.

A weak layer buried in late March exists as surface hoar and facets on north-facing slopes and a crust elsewhere. It has produced recent avalanche activity in the coastal areas. This layer may become reactive here too with new snow loads.

The middle of the snowpack is strong and contains numerous hard crusts. Near the ground, weak faceted crystals exist. There hasn't been avalanche activity on this layer recently, but it remains on our radar as it may become active with abrupt changes to the snowpack, such as rapid loading (heavy snowfall or rain) or prolonged warming.

Weather Summary

Thursday Night

Mostly cloudy with isolated flurries; 2-8 cm / 15 to 20 km/h southwest ridgetop wind / Temperature at treeline around -7 C

Friday

Mix of sun and cloud / trace / 25 to 35 km/h southeast ridgetop wind / Temperature at treeline around -4 C / Freezing level 1200 m

Saturday

Mostly cloudy with snow; 10 to 15 cm / 30 km/h south ridgetop wind gusts to 50 / Temperature at treeline around -3 C / Freezing level 1200 m

Sunday

Mostly cloudy; 3 to 6 cm / 15 to 25 km/h south winds / Temperature at treeline -4 C / Freezing level 1200 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 freshly wind loaded terrain features.
  • Cornice failure may trigger large avalanches.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

Wind Slabs

An icon showing Wind Slabs

Lingering wind slabs may remain reactive to human triggers on lee aspects at treeline and above.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 14th, 2023 4:00PM

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