Avalanche Forecast

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system. Forecast snowfall amounts are uncertain.

Continued snow through the Christmas holidays. Expect some heavier snowfall amounts Thursday with the passing cold front.  

Wednesday Night: 10- 15 cm of new snow accompanied by strong ridgetop wind from the southwest. Treeline temperatures near -5 and freezing levels 900 m.

Thursday: New snow throughout the day, heavy at times with 15-25 cm accumulation by the afternoon. Strong ridgetop wind from the southwest. Treeline temperatures near -2 and freezing levels 1100 m.

Friday: Flurries with new snow 5-10 cm with moderate to strong southwest wind. Treeline temperatures near -5 and freezing levels valley bottom.

Saturday: Mostly cloudy with some flurries 5-10 cm. Gusty ridgetop winds from the South and temperatures dropping to -12 with freezing levels valley bottom. 

On Tuesday, several natural loose dry and wind slab avalanches up to size 2 were reported. A recent MIN report also showed a human-triggered wind slab size 1 from a North aspect. Explosive control on Northerly aspects from 1800-2000 m produced loose dry and soft slab avalanches up to size 2. 

 

Widespread natural and human triggered storm slab avalanches will be likely through the forecast period. 

New snow and wind will likely build reactive storm slabs through Friday. This new snow will bury older wind slabs and existing surface hoar that has been reported throughout the Kootenay Pass and Nelson area. 

Below the new snow exists a well-consolidated upper snowpack which overlies a substantial crust that formed in early December. This crust is approximately 70-100 cm below the surface, 10 cm thick on average, and is present across all aspects to at least 2300m. A layer of weak facets (sugary snow) has been reported above this crust. 

The lower snowpack is composed of several early-season crusts. Snow depths at treeline average 150-200 cm. Below 1800 m the snowpack remains relatively shallow with 80-120 cm on average. The deepest snowpack can be found in the Kootenay Pass area.

• Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
• Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.