Avalanche Forecast
Issued: Dec 19th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
istorm,
Avalanche Canada
Areas like Pine Pass and Renshaw are in an avalanche cycle -- see Avalanche Section for the gossip. Continue to avoid avalanche terrain: stick to low angle slopes or play on flats without overhead hazard hanging above you.
Summary
Confidence
Moderate - Uncertainty is due to the track & intensity of the incoming weather system. Uncertainty is due to how the snowpack will react to the forecast weather.
Weather Forecast
No break in the storms quite yet.
SATURDAY NIGHT: 10 to 25 cm overnight, highest amounts on the westerly side of the mountains. Strong southwest wind. Freezing level near valley bottom.
SUNDAY: Wake up to new snow that fell overnight. Light snow and mostly cloudy during the day, continued moderate to strong southwest wind. Temps around -5 to -10 C near treeline.
MONDAY: Mix of sun and clouds, dry, light variable wind, and -10 C or colder temperatures.
TUESDAY: Very similar to Monday
Avalanche Summary
Pine Pass reports on Friday (courtesy of your local AvCan field team) included natural, accidental, and remotely triggered avalanches up to size 2.5. That's a big slide to get tangled up in -- one party of three were caught and partially buried (one up to the neck) or fully buried (with a deployed airbag). Slide were running at the bottom or the recent storm snow (down 40 cm) or last week's crust (65 cm deep). There was also a size 3 reported from Renshaw. Observations arelimited due to lack of visibility.
Snowpack Summary
Upper snowpack is made up of new or recent snow and with one more storm lined up to track through the storm snow will continue to build. The forecast wind will also build windslabs. In some areas in the north (Pine Pass, possibly Wolverine) there is surface hoar near the bottom of this recent snow -- which may be as deep as 50 or 60 cm.
Mid-pack is where you'll find a variety of crusts. Most reports haven't found them to be an issue.
Basal-pack, the basement also has some crusts. I suspect the layer to be potentially reactive in northern parts of the region, such as Pine Pass, but do not have observations to back this up.
Snow depths are approaching 200 cm around Pine Pass, Torpy and McBride and around 100 cm in the northeast around Tumbler Ridge. Â
Terrain and Travel
- Choose low-angled, sheltered terrain where new snow hasn't been wind-affected.
- Avoid areas with overhead hazard.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Storm Slabs
With incoming snow and wind loading avalanches on 30 degree or steeper slopes (moderate angle) where more than 30 accumulates remain very likely, especially if there's surface hoar below. Wind loaded slopes are especially suspect.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
I'm not sure if this surface hoar and crust combo extends into the alpine. However at lower elevations it is reactive down 50 to 70cm below the surface.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 21st, 2020 4:00PM
