Avalanche Forecast

Issued: Jan 21st, 2023 4:00PM

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

Avalanche Canada trettie, Avalanche Canada

Avoid wind loaded features, especially at ridge crests and on shallow rocky slopes. You may not see signs of instability but the layers are still there.

As the sun comes out, avoid travelling on or under sun exposed slopes.

Summary

Confidence

Moderate

Avalanche Summary

Over the past few days our field team has observed several small wind slab avalanches . Check out their latest MIN for more details.

Please continue to send in your observations through the MIN.

Snowpack Summary

New snow continues to gradually accumulate and be redistributed into wind slabs in exposed terrain. At lower elevations, a rain crust exists down around 20cm, with reported elevations extending up to 1800 m in the Cariboos and roughly 1200 m in the northern part of the region.

Snowpack depths are shallower than normal, and several buried weak layers have been a concern over the past few weeks. One is a recently buried surface hoar layer found 30 to 60cm deep in sheltered terrain features at treeline and above. At this same depth, a crust exists on steep south facing slopes. Another layer of facets, crust, and surface hoar was buried around Christmas and is now 50 to 90cm deep. Finally, a layer of large, weak facets buried in November is found near the bottom of the snowpack. This layer is likely most problematic in alpine terrain, where shallower avalanches could scrub down to these basal facets.

Recent observations suggest the buried weak layers are gaining strength, but not enough to trust them in high consequence terrain.

Weather Summary

Saturday Night

Cloudy with up to 5cm of new snow. Moderate to strong westerly winds and a low of -10 at 1800m.

Sunday

A mix of sun and cloud with the possibility of light flurries bringing trace amounts of new snow. Moderate northwest winds and a high of -8 at 1800m.

Monday

Stormy with up to 10cm of new snow expected. Strong to extreme west winds and a high of -5 at 1800m.

Tuesday

Stormy with up to 10cm of new snow expected. Strong westerly winds and freezing levels rising to 1400m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid being on or under sun exposed slopes.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Several buried weak layers remain a concern for human triggering. At treeline elevations, the main concern is surface hoar and crust layers in the middle of the snowpack, especially on steep convex openings. In the alpine, the main concern is weak facets at the bottom of the snowpack, especially on rocky slopes with variable snow depths.

These layers could become more sensitive to rider triggering on sun exposed slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

Winds have varied in the past few days. Wind slabs could be found on all exposed terrain at treeline and above.

Avoid thin rocky features near ridgetops where wind slabs and deeper layers are most likely to be triggered.

As the sun comes out wind slabs could be more sensitive to rider triggering.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 22nd, 2023 4:00PM