Avalanche Forecast

Issued: Mar 6th, 2023 4:00PM

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

Avalanche Canada jminifie, Avalanche Canada

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Wind slabs are aging but may still be triggerable. Spread your group out on large, connected pieces of slab-covered terrain in case of an unexpected surprise. Thin rocky areas remain a concern for triggering deeply buried weak layers.

Summary

Confidence

High

Avalanche Summary

No new avalanches were reported over the weekend and through Monday.

Prior to the weekend there were numerous reports of natural wind slab and cornice-triggered avalanches up to size 2.

Over a week ago, several large deep persistent slab avalanches were reported in the alpine, including a natural size 3 near Kispiox, a cornice-triggered size 2.5 at Hudson Bay and several explosive controlled size 2-3 near Ningunsaw.

Snowpack Summary

Firm, wind affected surface snow in exposed terrain features. Old wind slabs in cross loaded and lee features. Sun crusts on steep, solar aspects. Softer snow in very sheltered terrain features.

Several other crusts, layers of facets, or surface hoar can be found in the top 150 cm of the snowpack, but have not shown any significant avalanche activity or snowpack test results recently.

The lower snowpack consists of weak, basal facets which may become active with any rapid change or shock to the snowpack, such as heavy loading or dramatic warming.

Weather Summary

Monday night

Cold and clear as the outflow continues. Wind from the north at 20 km/h. Temperature -20˚C.

Tuesday

Cold and clear overnight clouds developing by the afternoon. 5 cm of new snow in the afternoon into the evening. Wind from the north 10km/h. Temperature rising to -5˚C by the afternoon.

Wednesday

Cloudy. 5 cm of new snow. Wind from the east at 10 km/h. Temperature from -10˚C to -5˚C.

Thursday

Clearing Wednesday night and clear through the day. Winds will be light and vary in direction. Temperature -17˚C in the morning warming to -5˚C by the afternoon.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Conditions may have improved, but be mindful that deep instabilities are still present.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Older wind slabs may require more time to bond with continued cold temperatures. Recent wind has varied in direction meaning wind slabs can be found on all aspects.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Weak, sugary crystals at the bottom of the snowpack produced large avalanches just over a week ago. These avalanches are most likely to be triggered by large loads such as cornice falls. However, in shallow snowpack areas they can also be triggered by the weight of a person and could propagate out to deeper snow resulting in large, destructive avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3.5

Valid until: Mar 7th, 2023 4:00PM