Avalanche Forecast

Issued: Dec 4th, 2023 4:00PM

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

Avalanche Canada jleblanc, Avalanche Canada

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Significant snow continues, with rising freezing levels and strong winds. Travel in the alpine is not recommended, and avoid exposure to overhead avalanche terrain.

Summary

Confidence

Moderate

Avalanche Summary

A natural widespread cycle occurred Sunday night, with several storm slab avalanches up to size 2 running from steep unsupported alpine and treeline features near Terrace. Reactivity is expected to increase with additional snow/rain, wind and rising temperatures on Monday night and Tuesday.

If you do go into the backcountry, head out with a very conservative mindset and consider submitting a Mountain Information Network report.

Snowpack Summary

The region received up to 25-50 cm of snow over the last 2 days, with heavy rain below 1000 m. The total of storm snow is now up to 50-80 cm in localized areas.

In the alpine, strong southerly winds have redistributed this new snow. A widespread crust, that varies in thickness and strength, is now found down 60 to 90 cm. The mid and lower snowpack appears to be well-bonded, but field observations have been limited early in the season. The height of snow at treeline is roughly 100-150 cm, and decreases drastically at lower elevations.

Weather Summary

A large and impactful weather system will continue to bring heavy precipitation and windy conditions. High-freezing levels are expected until mid-week.

Monday night

Heavy snow/rain; 15-20 cm. Southwesterly ridgetop winds gusting 90 km/h. Treeline temperatures reach 0 °C as the freezing level rises to 1500 m.

Tuesday

Heavy precipitations continue with 20-25 cm of snow /rain with an additional 5-10 cm overnight. Southerly ridgetop winds gusting 90 km/h. Treeline temperatures near -1 °C. Freezing levels return to 1200 m.

Wednesday

Light precipitations, 5-10 cm of snow/ rain. Moderate ridgetop winds up to 45 km/h. Treeline temperatures near -4 °C. Freezing levels lower to valley bottom.

Thursday

Periods of snow, Light ridgetop winds up to 20 km/h. Treeline temperatures near -6 °C. Freezing levels at valley bottom.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid exposure to overhead avalanche terrain during periods of heavy loading from new snow, wind or rain.
  • Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.
  • The more the snow feels like a slurpy, the more likely loose wet avalanches will become.

Problems

Storm Slabs

An icon showing Storm Slabs

Continued heavy precipitation, accompanied by strong southerly wind, will build fresh, reactive storm slabs that may be deeper and most reactive in wind-loaded terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Loose Wet

An icon showing Loose Wet

Loose wet avalanches will become increasingly likely on steep slopes as heavy rain will destabilize and soak the storm snow. Keep in mind that wet avalanches can be destructive due to their high density.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Dec 5th, 2023 4:00PM

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