Avalanche Forecast
Issued: Dec 30th, 2021 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
JSmith,
Avalanche Canada
Lingering wind slabs may remain reactive to human triggers on lee features at treeline and above.
Check out the latest Forecasters' Blog for tips on managing the ongoing Persistent Slab problem in this region.
Summary
Confidence
Weather Forecast
THURSDAY NIGHT: Partly cloudy / Light west wind / Low of -26
FRIDAY: Sunny / Light northwest wind / High of -21
SATURDAY: Mix of sun and cloud / Moderate northwest wind / High of -20
SUNDAY: Cloudy with flurries; 3-5 cm / Strong west wind / High of -13
Avalanche Summary
Several explosive triggered size 2 cornice failures were reported near Golden on Wednesday. The cornice failures only triggered small wind slabs on the slopes below.
Explosive control work on December 26th near Invermere produced large avalanches (size 2) on the crust formed in early December, found 40-70 cm deep in that area.
Snowpack Summary
Recent winds have created wind slabs on a variety of aspects. The recent snow may sit over a layer of weak surface hoar crystals at treeline and below.
The most notable layer of concern in the snowpack is a crust that was formed in early December and is now down 60-120 cm. Activity on this layer has been sporadic. It has generally been triggered on steep, rocky slopes, with a shallow or thin to thick snowpack.
This layer has created a low likelihood, high consequence scenario which is best managed through conservative terrain choices and disciplined backcountry travel techniques.
A late October facet/crust layer sits at the bottom of the snowpack above 1900m.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
Problems
Wind Slabs
Lingering wind slabs may remain reactive to human triggers on lee features at treeline and above.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A persistent slab problem formed by a crust down 50-120 cm has created a low likelihood, high consequence scenario that is difficult to forecast.
Avoid likely trigger spots such as steep, rocky slopes with a shallow or thin to thick snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 31st, 2021 3:00PM
