Avalanche Forecast

Issued: Mar 12th, 2023 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is high. Known problems include Storm Slabs.

Avalanche Canada jsmith, Avalanche Canada

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Forecast snow and wind are expected to trigger large natural avalanches on Monday.

Travel in avalanche terrain is not recommended.

Summary

Confidence

High

Avalanche Summary

Numerous rider triggered wind slabs up to size 1.5 were reported on primarily west and south aspects at treeline and above on Saturday.

One naturally triggered size 2 wind slab was reported on a south aspect at treeline near Kootenay Pass.

Forecast snow and wind are expected to form dangerous storm slabs that are reactive to human triggers at all elevations on Monday.

Snowpack Summary

Forecast snow and wind are expected to form fresh storm slabs that are reactive to human triggers at all elevations.

The storm snow will add to the 20-30 cm of recent snow which overlies a variety of surfaces. These include surface hoar (3-5 mm) on shady slopes, wind affected surfaces at treeline and above, and sun crust on sunny aspects.

A layer of surface hoar or sun crust (aspect dependent) can be found down 50-70 cm.

The lower snowpack includes a layer of weak sugary facets near the ground. These facets are slowly gaining strength and no recent avalanches have been reported on this layer. However, we continue to track the layer and watch for any signs of it becoming active.

Weather Summary

Sunday Night

Snow; 15-20 cm / Strong west ridgetop wind / Low temperature at treeline around -3 C / Freezing level 1200 m

Monday

Snow; 15-25 cm (rain below 1500 m); another 10-20 cm overnight / Strong southwest ridgetop wind / High temperature at treeline around 2 C / Freezing level rising to 1700 m

Tuesday

Mix of sun and cloud / Light southwest ridgetop wind / High temperature at treeline around -2 C / Freezing level 1200 m

Wednesday

Sunny / Light west ridgetop wind / High temperature at treeline around 0 C / Freezing level 1500 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
  • Stick to non-avalanche terrain or small features with limited consequence.
  • Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Forecast snow and wind are expected to form large storm slabs that are reactive to human triggers at all elevations on Monday.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely - Certain

Expected Size

1 - 2.5

Valid until: Mar 13th, 2023 4:00PM