Avalanche Forecast
Issued: Dec 4th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Wet.
jleblanc,
Avalanche Canada
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
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
Expected Size
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
Expected Size
Valid until: Dec 5th, 2023 4:00PM
