Avalanche Forecast

Issued: Mar 26th, 2023 4:00PM

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

Avalanche Canada llarson, Avalanche Canada

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Continue to manage small sluffs, that could turn into a larger loose dry avalanche.

Even short windows of sun effect can turn steep south-facing slopes moist so pay attention to surface conditions if the sun starts to peak out.

Summary

Confidence

Moderate

Avalanche Summary

Several loose dry size 1 reported in the forecast region.

Snowpack Summary

Recent snow accumulated over the past week overlies a crust on all terrain except north-facing slopes treeline and above. On these high northerly slopes, soft snow overlies facets and surface hoar to mountain tops.

30-50 cm down there is another sun crust on sunny aspects and surface hoar (3-10 mm) on isolated shady and sheltered slopes. The distribution of this surface hoar is spotty.

The remainder of the mid-snowpack is generally strong but the lower snowpack is a different story. The November facets are still prominent at the base of the snowpack. They are showing signs of improving but this layer remains a significant concern for human triggering in rocky, shallow, or thin-to-thick snowpack areas at treeline and above. Small avalanches and cornice falls also have the potential to trigger this deep layer.

Weather Summary

Sunday Night

Mostly cloudy with the possibility of convective flurries bringing up to 5 cm of new snow. Light variable winds and treeline temperatures -6 °C.

Monday

A mix of sun and cloud with the possibility of light flurries bringing a few cm of new snow. Light northwest winds and treeline temperatures of -6 °C.

Tuesday

Clear skies with no new snow expected. Light northerly winds and treeline temperatures of -6 °C.

Wednesday

Increasing clouds with no new snow expected. Light northeast winds and treeline temperatures of -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Watch your sluff: it may run faster and further than you expect.
  • Minimize your exposure time below cornices.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth, but large triggers such as cornice failures or smaller avalanches in motion have the potential to produce very large avalanches with surprisingly wide propagation. Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2.5 - 3.5

Loose Dry

An icon showing Loose Dry

New snow remains unconsolidated with cool temperatures and calm to light winds. The accumulated new snow sits on variable surfaces of hard wind-pressed, sun crust and some remaining pockets of soft snow on north-facing slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Mar 27th, 2023 4:00PM

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