Avalanche Forecast

Issued: Mar 7th, 2021 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

Wind slabs may be triggered by riders at higher elevations. The consequence of triggering a deeper weak layer would be high.

Summary

Confidence

High -

Weather Forecast

SUNDAY NIGHT: Clear skies, 20 km/h south wind, alpine temperature -5 C.

MONDAY: Mix of sun and cloud, 10 km/h southwest wind, alpine temperature -5 C, freezing level 900 m.

TUESDAY: Clear skies, 20 km/h northwest wind, alpine temperature -6 C.

WEDNESDAY: Mix of sun and cloud, 30 km/h northwest wind, alpine temperature -5 C.

Avalanche Summary

A large (size 2.5) persistent slab avalanche released naturally west of Terrace along Highway 16 on Saturday out of a south-facing avalanche path. Some small (size 1 to 1.5) storm and wind slab avalanches were also triggered by riders. Otherwise, many loose wet avalanches were observed during the heat of the day.

Snowpack Summary

Moderate wind from variable directions has produced wind slabs in exposed terrain. The most likely place to find them is immediately adjacent to ridges at treeline and alpine elevations. Relatively mild conditions and sunny skies could weaken the snow on southerly aspects and make cornices more likely to be triggered.

Around 100 to 200 cm overlies a persistent weak layers buried in mid-February that may still be a concern in parts of the region. The layer consists of feathery surface hoar crystals in areas sheltered from the wind and sugary faceted grains that formed during February's cold snap. Avalanche activity on this layer has mostly occurred west of Terrace along Highway 16 in the past week, but the layer could still be of concern anywhere it exists.

There are currently no layers of concern in the mid and lower snowpack.

Terrain and Travel

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Avoid exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs may be found in steep terrain features near ridges. The wind has varied in direction, so wind slabs may be found on all aspects. Be cautious if you enter steep features and look for signs of instability.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Around 100 to 200 cm of snow may overly a persistent weak layer buried in mid-February. The likelihood of triggering the layer has decreased since recent loading over the past few days, but the consequence of doing so would be high.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 8th, 2021 4:00PM