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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Recent snow continues to be loaded into lee terrain features by northwest wind. Watch for signs of instability in wind-affected snow as you gain elevation. The best riding can be found in sheltered areas around treeline.

Summary

Confidence

Moderate - Uncertainty is due to limitations in the field data.

Weather Forecast

Thursday night: Flurries bringing a trace. Strong northwest wind. Alpine temperatures around -6. Freezing level valley bottom.

Friday: Flurries bringing around 5 cm. Strong northwest wind. Alpine high temperatures around -5. Freezing level 1000 m.

Saturday: Up to 10 cm new snow. Strong southwest wind. Alpine high temperatures around -5. Freezing level 1000 m.

Sunday: 5-15 cm new snow. Moderate westerly wind. Alpine high temperatures around -10. Freezing 500 m.

Avalanche Summary

Recent reports of avalanche activity have come almost exclusively from the southwest of the region. In the last few days, natural, explosive and skier triggered wind slab avalanches averaging size 2 have been reported on east to southeast aspects at treeline and alpine elevations. Below treeline, natural loose wet and wet slab avalanches around size 2 are suspected to have run during the storm Tuesday night. Explosive control work on Wednesday produced loose wet and wet slab results size 1-1.5 below 1000 m.

Snowpack Summary

15-20 cm of recent snow has seen widespread wind effect in exposed alpine terrain with pockets of wind slab in lee features. Below 1300 m the surface is crusty and/or moist depending on elevation and time of day. Between these wind- and temperature-affected elevations, soft snow may be found in sheltered areas around treeline.

Buried 50-90 cm deep, a layer of spotty surface hoar crystals may exist on sheltered north aspects as well as a melt-freeze crust on south aspects and below 1450 m. Recent observations suggest warm temperatures have aided bonding at this interface. 

The mid and lower snowpack is reported as well settled and strong in most areas. However, weak facets exist at the base of the snowpack in the more shallow snowpack zones within much of the region and always have the potential of being triggered on steep, rocky slopes with a shallow or thin to thick snowpack; especially with large loads such as a cornice fall.

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.

Problems

Wind Slabs

An icon showing Wind Slabs

Watch for wind slabs in lees of ridge crests and roll-overs at upper elevations.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

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