Avalanche Forecast

Issued: Jan 6th, 2023 4:00PM

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

Avalanche Canada llarson, Avalanche Canada

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Avoid steep, rocky terrain where the snowpack is shallow. It is these isolated features where human triggering of the deep persistent weak layers is still possible.

Summary

Confidence

Moderate

Avalanche Summary

Two large natural avalanches were reported in the west of the region that occurred in a steep, shallow, rocky terrain features above 2000 m

Going forward these isolate terrain features: Thin, rocky areas where the melt-freeze crust is not found or less robust should be avoided.

Snowpack Summary

New snow starting with flurries tonight and continuing through tomorrow will bury/further bury various surfaces. These surfaces consist of crusts on steep south-facing slopes, surface hoar that developed over the past few days, and in sheltered areas 30 to 40 cm of soft snow.

A hard melt-freeze crust can be found up to 2000 m. Where it is robust enough to do so, this crust will make deeper instabilities difficult to trigger.

Above 2000 m where the December 26 melt-freeze crust is thin or non-existent the two persistent weak layers may still be triggered in steep, shallow, rocky terrain features. The two layers of concern are:

  • A surface hoar/crust layer buried in mid-December down 60 to 80 cm.

  • A surface hoar/facet layer buried in mid-November down 80 to 150 cm deep.

Weather Summary

Friday night

Cloudy with clear breaks, the chance of flurries possibility of freezing rain, 10 to 20 km/h southwest wind, treeline temperature around -5 °C.

Saturday

Cloudy, 5 to 10 cm new snow, to 20 to 40 km/h, treeline temperature -4 °C.

Sunday

Cloudy, 5 to 10 cm of new snow, heaviest overnight, 20 to 40 km/h southwest winds, treeline temperatures -5 °C

Monday

Cloudy with possible sunny breaks, with flurries tapering through the morning. 20 to 30 km/h southerly winds, treeline temperatures -6 °C

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
  • Be mindful that deep instabilities are still present and have produced recent large avalanches.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The most recent activity on this layer has been at elevations above a melt-freeze crust that formed on December 26th. Thin, rocky areas above 2000m where the December 26th melt-freeze crust is thinner or non-existent continue to be areas of concern to trigger both Dec and Nov persistent weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3

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

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