Avalanche Forecast

Issued: Mar 25th, 2021 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 ahanna, Avalanche Canada

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Last chance to get your powder fix before temperatures get warm in the alpine this weekend. Be careful as you transition into wind affected terrain. Recent snow may become increasingly sensitive to triggering if the sun comes out Friday.

Summary

Confidence

High -

Weather Forecast

Thursday night: Flurries bringing around 5 cm. Light wind. Alpine temperatures around -7.

Friday: Mix of sun and cloud. Light to moderate northwest wind. Alpine high temperatures around -2. Freezing level 1800 m.

Saturday: Sunny. Moderate westerly wind. Alpine high temperatures around 0. Freezing level 2300 m.

Sunday: Flurries. Strong southwest wind. Alpine high temperatures around 0. Freezing level 2400 m.

Avalanche Summary

On Wednesday, neighboring Waterton National Park reported size 1 loose dry activity on steep solar aspects. Solar induced activity can be expected as skies clear over the next couple of days.

On Monday and Tuesday, we received a few reports of size 1 natural and explosive-triggered wind slabs in steep, unsupported alpine features in the south of the region where recent snowfall amounts have been greatest.

Snowpack Summary

20-30 cm of new snow has been accumulating incrementally over recent days. This recent snow overlies a crust on all but alpine northerly aspects. The extent of wind effect in the alpine varies through the region, windy southern areas reporting stripped windward aspects, while neighboring K-country reported only isolated wind effect as of Wednesday.

Around 30 to 60 cm of snow sits above a layer of sugary faceted grains that were buried in mid-February. In some areas, there may be an old layer of feathery surface hoar or facets from late January down 50 to 80 cm deep. There have been no reported avalanches on either of these layers in the region since March 9th in the Crowsnest.

The mid pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack.

Terrain and Travel

  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Problems

Wind Slabs

An icon showing Wind Slabs

Watch for wind loaded pockets in lee terrain features such as beneath ridge crests and roll-overs.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Mar 26th, 2021 4:00PM