Avalanche Forecast
Issued: Dec 6th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
ldreier,
Avalanche Canada
Southwest wind formed reactive wind slabs in the alpine and at treeline. At treeline elevations, slabs might sit on a buried weak layer. Be cautious when transitioning into wind affected terrain and investigate the bond of the new snow.
Summary
Confidence
Avalanche Summary
No new avalanches have been observed or reported in this region. However, note that we have had very few field observations.
Snowpack Summary
Up to 25 cm new low-density snow covers up to 30 cm of older settling snow. Down 40-60 cm is a melt-freeze crust from mid-November. To the east, in the Columbia and Kootenay-Boundary forecast regions, a layer of surface hoar (on a crust) down 40-80 cm has been quite reactive with extensive reports of whumpfing and cracking, several skier-triggered and a few natural avalanches up to size 2. This layer is found within this forecast region, but we need more field observations to determine its extent and sensitivity. Snowpack depths exceed 100 cm at upper elevations.
Weather Summary
Tuesday night
Cloudy with a trace of new snow. Southwest wind 20-30 km/h. Treeline temperature low -10 °C.
Wednesday
Cloudy with a trace of new snow. Southwest wind 20-30 km/h. Treeline high temperature -8 °C.
ThursdayMix of sun and cloud, with isolated flurries and up to 3 cm new snow. Southerly wind 50-60 km/h. Treeline high temperature -6 °C.
FridayMix of sun and cloud, with isolated flurries and up to 5 cm new snow. Southwest wind 20-30 km/h. Treeline high temperature -7 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Closely monitor how the new snow is bonding to the old surface.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
Problems
Wind Slabs
Southwest wind formed fresh wind slabs in the alpine and at treeline elevations.
Reports further east describe a weak layer of surface hoar buried 40-80 cm deep (check out the Avalanche Forecast to the east). Skiers triggered several avalanches up to size 2 on this layer, and extensive whumpfing and cracking was reported. We have limited observations this year, but this problem could also be encountered in this avalanche forecast region. Be cautious when transitioning into wind affected terrain. Where fresh wind slabs sit on a weak layer of surface hoar, slabs may extend into treeline elevations, and be more reactive and result in larger avalanches than expected.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 7th, 2022 4:00PM
