Avalanche Forecast
Issued: Jan 9th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
zryan,
Avalanche Canada
Limited field observations mean uncertainty is high.
Choose conservative terrain as we assess the snowpack after several weeks of prolonged cold temperatures and a significant amount of new snow and wind.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
Sunday Overnight: Snowfall easing. Strong southerly winds. Alpine temperatures rise to -10 C.
Monday: Snowing, up to 5 cm accumulation. Moderate to strong southerly winds. Alpine temperatures around -10 C.
Tuesday: Light snowfall. Moderate to strong southwest winds. Alpine temperatures around -8 C.
Wednesday: Partially cloudy, light flurries. Alpine temperatures around -12 C. Light southerly winds.
Avalanche Summary
Last week, a natural avalanche cycle occurred in White Pass. This was a result of sustained north winds redistributing the 30-40cm of New Years Eve storm snow. This MIN from Wednesday describes widespread size 2 avalanches, running well into treeline. Avalanches also occurred further inland along the highway corridor on January 4.
Snowpack Summary
Yesterday's 10-30 cm of new snow will continue to be redeposited by strong southerly winds into fresh wind slabs in the alpine and treeline. These new wind slabs overlie a heavily wind-affected surface of old harder wind slabs and sastrugi. The new snow will probably bond poorly to the old hard surface and human triggering might remain likely.Â
Below the new snow, many days of northerly outflow winds last week formed thick, hard slabs, that overlie a weak faceted (sugary) surface. These older hard slabs will probably be stubborn or unreactive to human triggering, but with limited observations in the past week, we would be treating them with caution.Â
Terrain and Travel
- In times of uncertainty conservative terrain choices are our best defense.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Avoid terrain traps where the consequence of any avalanche could be serious.
Problems
Wind Slabs
New snow and southerly wind may have formed reactive wind slabs in lee areas in the alpine and treeline.
Older hard slabs exist on all aspects from last week's northerly outflow winds. We expect these slabs to be quite stubborn to human triggering, but would be treating them with caution, as they overlie a weak layer of sugary facets.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 10th, 2022 4:00PM
