Avalanche Forecast

Issued: Feb 7th, 2023 4:00PM

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

Avalanche Canada mbender, Avalanche Canada

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Up to 30cm of new snow overnight is likely forming reactive storm and wind slabs. Avoid avalanche terrain at higher elevations and give the storm snow time to settle out.

Summary

Confidence

Moderate

Avalanche Summary

On Friday, a large (size 2), rider triggered, windslab avalanche was reported south of Crowsnest Pass. It occured in an open, cross-loaded feature below tree line on a north facing slope.

On Saturday, in neighboring Waterton National park, a similar but smaller (size 1.5) rider triggered avalanche occured on a southeast facing slope below treeline.

Wind slabs may linger directly lee of ridges at high elevations. See this MIN post for an example.

Please continue to share any observations or photos on the Mountain Information Network.

Snowpack Summary

10 to 20 cm of recent snow coupled with moderate to strong southwest winds has built wind slabs in lee and crossloaded features at alpine and treeline elevations, and in open features below treeline. A melt-freeze crust can be found at 2100 m and below at variable depths, on the surface on windward slopes, and buried 15 to 20 cm in lees. Wind slabs may be more reactive where they sit on this crust.

The middle of the snowpack is consolidated. Weak faceted grains exist near the base of the snowpack.

The average snowpack depth is 120 cm. Up to 200 cm can be found in wind-loaded areas.

Weather Summary

Tuesday Night

Cloudy with flurries, accumulation 5-10cm. Moderate to strong southwest ridgetop wind. Treeline temperatures -4 °C, freezing level 1200 m.

Wednesday

Mix of sun and cloud. Moderate northwest or west ridgetop wind. Treeline temperatures around -6 °C.

Thursday

Mix of sun and cloud. Strong west or southwest ridgetop wind. Treeline temperature -3 °C.

Friday

Mix of sun and cloud. Strong west ridgetop wind. Treeline temperature -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be careful to keep storm day fever from luring you out into bigger terrain features.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

New snow and wind have likely formed new storm and wind slabs

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2

Valid until: Feb 8th, 2023 4:00PM