Avalanche Forecast
Regions: South Coast Inland.
Freezing level rising and temperature warming will increase the avalanche danger thoughout the day. Large cornices may become weak and easy to trigger.
Confidence
Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.
Weather Forecast
The freezing levels will rise significantly to over 2000 metres on Sunday but with no precipitation forecast.
SATURDAY NIGHT: Cloudy with scattered flurries, accumulation 1 to 3 cm, 30-50 km/h southwest wind, alpine temperature -10 C with freezing level at 500 m.
SUNDAY: A mix of sun and cloud, no precipitation, 30-40 km/h southwest wind, alpine temperature 0 C with freezing level rising to 2100 m.
MONDAY: Cloudy with sunny periods, no precipitation, 20-40 km/h southwest wind, alpine temperature -3 C with freezing level at 1500 m.
TUESDAY: Snow and rain mixed, accumulation 10 to 20 cm, 40-60 km/h southwest wind, alpine temperature 0 C with freezing level at 1800 m.
Avalanche Summary
A few natural avalanches were observed over the last few days, including a wind slab at higher elevation triggered by a cornice fall, as well as an avalanche below treeline near valley bottom (see here for details). Loose wet avalanche activity was observed at lower elevations in the south of the region on Friday, likely from Thursday night's warm-up.
Snowpack Summary
The last few days snowfall (15-35 cm) were associated with strong southwest wind, which likely formed new wind slabs in lee terrain features. This recent precipitation adds to the 50+ cm of snow that has fallen since January 1, which may overly sugary faceted grains that formed during the cold spell in late December.
Around 80 to 200 cm deep, a weak layer of faceted grains may be found above a melt-freeze crust that formed in early December. The layer is most prominent between 1700 and 2100 m. The last observed avalanche on this layer was around December 24, suggesting that this layer has become dormant. The most likely place to trigger it would be in thin, rocky snowpack areas.
The lower snowpack is well-settled and strong.
Terrain and Travel
- Cornices become weak with daytime heating.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Cornice failures could trigger very large and destructive avalanches.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Avalanche Problems
Cornices
With rising freezing level and temperature warming during the day, large cornices developed with recent snow and wind may become weak and easy to trigger. Also, keep in mind that cornice failure may trigger large avalanches.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 2.5 - 3.5
Wind Slabs
Recently formed wind slabs may remain reactive to human traffic. The slabs formed from strong southeast to southwest wind. Use particular caution when entering lee terrain features near ridges.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1.5 - 2.5