Avalanche Forecast

Issued: Jan 9th, 2023 4:00PM

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

Avalanche Canada jleblanc, Avalanche Canada

Email

Dangerous avalanche conditions exist.

Make conservative terrain choices by choosing low-angle slopes and avoid overhead hazards.

Summary

Confidence

Moderate

Avalanche Summary

A skier accidentally triggered a small storm slab on south-west alpine lee feature near Blackcomb. Numerous size 1 wind/storm slabs were also human-triggered on steep terrain at treelien and above near Whistler. Limited travel and visibility in the mountains prevented recording more activity. The likelihood of avalanches will increase with the arrival of the forecast weather.

Snowpack Summary

Up to 35 cm of new snow has fallen into the region since the weekend. Ongoing southerly and previous northerly winds have affected the storm snow in any open terrain and near ridgelines. On sheltered slopes, up to 60 cm of powder storm snow can be found. Snow is heavy and moist at lower elevations.

A thick widespread crust formed in late December is down 40 to 70 cm. In the alpine, it is thin and breakable. Professionals are concerned that small avalanches may run down to this crust and create larger-than-expected avalanches.

Near the base of the snowpack, a weak facet/crust layer from mid-November can be found and remains a concern. In general, the snowpack is weak, faceted, and shallow.

Weather Summary

A frontal band will generate periods of moderate snowfalls Monday night. Overcast skies and dry conditions are expected by midday Tuesday. A deeper system is expected to push heavier snowfalls into the region late evening Wednesday.

Monday night

Stormy 10-15 cm, moderate southerly winds gusting 60 km/h, freezing levels around 1200 m, low of -4C at treeline.

Tuesday

Stormy 5-10 cm ending by midday, moderate southeasterly winds gusting 45 km/h, freezing levels rising to 1500 m, high of +1C at treeline.

Wednesday

Snow 5-10 cm starting midday at higher elevations, moderate southerly winds gusting 45 km/h, freezing levels around 1200 m, high of -2C at treeline.

Thursday

15-25 mm of wet snow/rain, moderate southerly winds gusting 60 km/h, freezing levels around 1800 m, high of 0C at treeline.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

Problems

Storm Slabs

An icon showing Storm Slabs

Strong southerly winds and additional overnight snowfalls will create touchy fresh slabs. Storm slabs may be most reactive where wind has loaded deep deposits into leeward terrain features in the alpine and treeline. Be aware that slab avalanches could step down to deeper layers and produce larger-than-expected avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 10th, 2023 4:00PM