Avalanche Forecast
Issued: Dec 21st, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
TRettie,
Avalanche Canada
Use extra caution in wind effected terrain. Wind slab will be sensitive to rider traffic. If more than 25cm of new snow is observed consider the hazard in the alpine and treeline to be considerable.
Summary
Confidence
Weather Forecast
Tuesday night: Up too 10cm with strong Northwest winds. Low of -13 at 900m.
Wednesday: some flurries ending around noon. Moderate North winds And a high of -12 at 900m.
Thursday: no new snow expected. Light to moderate North wind and a high of -14 at 900m.
Friday: sunny with no new snow expected. Moderate North winds with a high of -16 at 900m.
Avalanche Summary
Several natural wind slabs up to size 2.5 were reported to have released from ridgetops.
Old wind slabs on cross loaded features from outflow winds were also reported over the last 48 hours.
Snowpack Summary
New wind slab will build on all aspects as a result of precipitation and strong variable winds on Tuesday. This will overlie old wind effected surfaces in the treeline and alpine.
The December 18th surface hoar/facet layer is down 15cm, the surface hoar was observed up to 12mm in both the treeline and below treeline. It is likely only a problem in sisolated locations in the treeline where wind slab has formed above it.
The December 7 persistent weak layer is now typically down 50-70 cm, though some professional operations are saying that it is getting harder to find. This interface may include a crust, facets, or surface hoar.
Snowpack depths vary greatly across the region, expect to find anywhere from 100-300 cm of snow around treeline.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Seek out sheltered terrain where new snow hasn't been wind-affected.
Problems
Wind Slabs
New wind slab will form throughout the day on Tuesday in treeline and alpine. Cross loaded features from previous outflow will likely still be rider triggerable. Other areas of additional concern are isolated features in the treeline where wind slab could have formed over surface hoar creating a heightened sensitivity to triggering.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 22nd, 2021 4:00PM
