Avalanche Forecast
Issued: Dec 4th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Wind Slabs.
Tereza Turecka,
As natural activity tapers off don't let yourself be fooled. We are entering low probability high consequence state of affairs. November crust is still prevalent and thick to thin spots are of most concern.
Summary
Weather Forecast
Sunday: A mix of sun and cloud. Precipn: Nil. Alpine temp: High -17 °C. Mostly light wind occasionally gusting to 35 km/h. Freezing level at valley bottom.Monday: Same as SundayTuesday: Cloudy with sunny periods and isolated flurries. Precipitation: Trace. Alpine temperature: Low -17 °C, High -12 °C. Ridge wind west: 15 km/h. FL at valley bottom.
Snowpack Summary
About 40 cm of snow fell from Nov 30 to Dec 1. Light to moderate SW winds blew the storm snow into wind slabs or stripped windward features to ground. The storm snow came in warm but it surprisingly remains dry and light except at low elevations where it rained. The midpack is supportive over a crust /facet /depth hoar combo near the ground.
Avalanche Summary
Friday's patrol noted a reduction in natural activity yet a couple of recent size 3's deep slabs running full path were recorded. Thursday's explosive control work observed an avalanche cycle up to size 3 being wind and deep persistent slabs on the ground or the basal crust. Two size 3s were observed at Maligne north of Joffre Creek on Thursday.
Confidence
The weather pattern is stable
Problems
Deep Persistent Slabs
Natural activity is decreasing as the recent new snow stabilizes, however, triggering this layer would be a high consequence event so cautious decisions and a thorough investigation is necessary.
- Use caution on open slopes and convex rolls
- Avoid thin rocky or unsupported terrain features.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
A triggered windslab has a potential to step down to deeper instabilities with a more destructive potential. Consider testing smaller slopes before committing to a terrain with potential for larger propagation. Watch for hollow sounds and cracking.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
- Use caution in lee areas. Recent wind loading have created wind slabs.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 5th, 2021 4:00PM
