Avalanche Forecast

Issued: Mar 11th, 2023 4:00PM

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

Avalanche Canada MW, Avalanche Canada

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Solar effect has been less influential than originally forecast and the snowpack structure has changed very little over the past week. The hazard remains moderate in the alpine and at treeline due to uncertainty regarding the reactivity of our deep persistent slab problem.

Shaded, polar slopes will have better skiing at treeline and below.

Summary

Confidence

Moderate

Avalanche Summary

Avalanche control using explosives on Hwy 93N resulted in few wind slabs and numerous loose dry avalanches up to size 2 on Wednesday, March 8.

No new natural avalanche activity observed on Maligne Road or Icefields Parkway today.

Don't forget to post avalanche observations to the MIN.

Snowpack Summary

A weak sun crust can be found on sun-exposed slopes at lower elevations. Wind sheltered areas and sun-protected slopes have 20 to 40cm of low density facetted snow. There is extensive wind effect at tree line and above from previous SW winds.

The mid and lower snowpack is generally weak and faceted with depth hoar lingering at the base. Snowpack depth varies from 60 to 160cm.

Weather Summary

Sunday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: High -8 °C.

Ridge wind southwest: 10-25 km/h.

Freezing level at valley bottom.

Monday

Snow.

Accumulation: 17 cm.

Alpine temperature: Low -8 °C, High -3 °C.

Ridge wind southwest: 15-35 km/h.

Freezing level rising to 1700 metres.

Tuesday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -17 °C, High -10 °C.

Ridge wind southwest: 15 km/h gusting to 40 km/h.

Freezing level at valley bottom.

Freezing level rising to 1600 metres.

Detailed weather forecasts from Avalanche Canada: https://www.avalanche.ca/weather/forecast

Terrain and Travel Advice

  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

Wind Slabs

An icon showing Wind Slabs

Previous moderate to strong SW winds have formed wind slabs in exposed areas at tree line and in the alpine.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Use caution is thin snowpack areas where human traffic may be able to trigger this layer. Large triggers such as cornice fall or wind slab avalanches may also trigger this layer resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3.5

Valid until: Mar 12th, 2023 5:00PM