Avalanche Forecast

Issued: Apr 10th, 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

Email

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

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

Summary

Confidence

Moderate

Avalanche Summary

A very large (size 3) naturally triggered wind slab avalanche was reported on a northwest aspect in the alpine on Sunday. The avalanche may have failed on a layer of facets buried in early April.

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

Around 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

Monday night

Partly cloudy / 10 km/h southeast ridgetop wind / Temperature at treeline around -7 C / Freezing level valley bottom

Tuesday

Mostly cloudy with isolated flurries; 3-10 cm / 20 km/h west ridgetop wind / Temperature at treeline around -4 C / Freezing level 1200 m

Wednesday

Mix of sun and cloud / 30 km/h west ridgetop wind / Temperature at treeline around -6 C / Freezing level 1100 m

Thursday

Mostly cloudy / 20 km/h southwest ridgetop wind / Temperature at treeline around -6 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 freshly wind loaded terrain features.
  • 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, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 11th, 2023 4:00PM