Avalanche Forecast

Issued: Feb 3rd, 2024 3:30PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs, Persistent Slabs and Deep Persistent Slabs.

Avalanche Canada JMackenzie, Avalanche Canada

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Up to 10cm of fresh snow with another 10cm on the way with moderate winds. Hazard levels will depend significantly on how well the new snow bonds with the underlying crusts. Take extra time to evaluate this bond as you travel through different elevation bands and on various aspects. Choose conservative terrain for the next few days.

Summary

Confidence

Low

Avalanche Summary

No new avalanche were observed, but weather conditions made for limited observations.

Snowpack Summary

A big change is occurring. Up to 10cm of warm, moist snow has fallen at Treeline through the day on Saturday. This snowfall started off very warm, so hopefully it will stick to the recently formed raincrust underneath. However, with the deep penetration of the previous rainfall and warm temps, buried layers of moist snow will persist for some time. Travel may be difficult until the temperatures cool down and freeze the rain saturated layers. Another 10cm of slightly cooler snow is possible in the next 24 hours, with moderate NE winds. This will likely lead to fresh wind slab development on NW, W and SW slopes, especially at higher elevations. In alpine areas, this incoming snow may not bond well to the previous surfaces, but at lower elevations it likely will. Backcountry users should be very curious over the next few days, dig frequently, and carefully evaluate the effects of this big weather change at various elevations and on various aspects.

Weather Summary

It finally snowed again! Up to 10cm at Treeline fell through the day on Saturday, with the Snowfall Warning continuing into Sunday. An additional 10cm is possible. Initially the winds will be moderate from the NE, and then it sill switch to light SW late Sunday afternoon. Temperatures should range from -12 to -9C. The snowfall should end around midnight Sunday, with mainly cloudy conditions by Monday morning.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Wind slabs may be poorly bonded to the underlying crust.
  • Wind slabs are most reactive during their formation.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Watch for unstable snow on specific terrain features, especially when the snow is moist or wet.

Problems

Wind Slabs

An icon showing Wind Slabs

Rapid wind loading and recent snowfalls will promote wind slab development at upper elevations, including reverse wind loading on westerly slopes. The new snow may not bond well to the underlying crusts.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

This will still be an issue in areas that escaped the heat, as there is no previous crust to hold the snowpack together. Increased load may make this layer more reactive.

Aspects: North, North East, East, West, North West.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

This layer is shielded by 2 crusts, but is still triggerable from thin to thick transitions. Very much a low probability, high consequence situation.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Valid until: Feb 4th, 2024 4:00PM

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