Avalanche Forecast

Issued: Feb 29th, 2024 4:00PM

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

Avalanche Canada swerner, Avalanche Canada

Email

Dangerous avalanche conditions continue. Natural and human-triggered avalanches are likely.

Stick to simple, non-avalanche terrain without exposure to overhead slopes.

Summary

Confidence

Moderate

Avalanche Summary

No new reports by 4 pm Thursday.

On Wednesday, a natural storm slab avalanche cycle was reported at all elevations up to size 1.5. We suspect larger avalanches have occurred but field observations tend to be limited during the storm. Operators who were out reported that the new snow was very reactive to rider triggers and showed a poor bond to the old, firm snow beneath.

Natural, and human-triggered avalanche activity will likely continue on Friday.

Snowpack Summary

50 to 100 cm of storm snow overlies wind-affected surfaces and old wind slabs in exposed areas at all elevations.

Multiple weak layers exist in the upper and mid snowpack. The most concerning weak layer is found down 50 to 120 cm and is composed of a layer of facets or in isolated areas preserved surface hoar above a thick crust. This layer is the culprit of recent remotely-triggered avalanches in low-angle terrain. Professionals are concerned about how this layer will react to the new snow load.

Weather Summary

Thursday Night

Cloudy with snow 5 to 10 cm. Ridgetop wind 25 gusting to 60 km/h southwest ridgetop wind. Treeline temperature -7 °C. Freezing levels valley bottom.

Friday

Cloudy with sunny periods. 15 to 45 km/h south ridgetop wind. Treeline temperature -5 °C. Freezing level 800 m.

Saturday

Cloudy with sunny periods and isolated flurries. 15 to 35 km/h southeast ridgetop wind. Treeline temperature -7 °C. Freezing level hovers around 900 m.

Sunday

Cloudy with sunny periods and isolated flurries. Light southeast ridgetop wind. Treeline temperature -7 °C. Freezing level hovers around 900 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Brief periods of sun could quickly initiate natural avalanche activity.

Problems

Storm Slabs

An icon showing Storm Slabs

Storm snow and strong winds have built touchy slabs. Deeper deposits are expected in north and east facing terrain around ridgelines.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A weak layer of facets or surface hoar above a thick crust persists in the snowpack. If triggered storm slab avalanches may step down to this layer resulting in very large, destructive avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 3.5

Valid until: Mar 1st, 2024 4:00PM