Avalanche Forecast
Issued: Nov 29th, 2021 4:00PM
The alpine rating is Loose Wet and Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeNew snow followed by heavy rain is Tuesday's recipe for rapidly changing and dangerous avalanche conditions.
Summary
Confidence
High -
Weather Forecast
Monday night: Cloudy with increasing wet flurries bringing 5-10 cm of new snow. Moderate southwest winds.Â
Tuesday: Wet flurries transitioning to heavy rain in the afternoon; 30-50 mm accumulation. Strong south or southwest winds, increasing over the day and overnight. Treeline temperatures rising from around 0 to +4 over the day as freezing levels climb from 1400 to 2900 metres.
Wednesday: Heavy rain; 40 mm accumulation. Strong south or southwest winds. Treeline high temperatures around +4.
Thursday: Mainly clear. Light to moderate northwest winds. Treeline high temperatures around -4.
Avalanche Summary
Tuesday's forecast suggests we will see a rapid evolution of avalanche conditions over the day. Depending on freezing levels and snowline elevations, we could see substantial storm slabs form in the region's upper elevations before they are hammered by rain in the afternoon. A rapid transition from widespread touchy storm slabs to equally touchy wet loose avalanche conditions is expected to occur over the day.Â
Snowpack Summary
Heavy rain has affected the snowpack at all elevations. The current forecast suggests we may see 15-25 cm of new snow accumulate before Tuesday afternoon when heavy rain takes over and once again drenches the snowpack at all elevations.
Average treeline snow depths are around 80-100 cm with much of treeline and all but the uppermost below treeline elevations still below threshold depths for avalanches.
Terrain and Travel
- Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
- The first few hours of rain will likely be the most dangerous period.
- The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
Problems
Loose Wet
New snow followed by a deluge of rain will breathe new life into wet loose avalanche problems on Tuesday. The more new snow has accumulated before the transition to rain occurs, the greater the danger will be.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
Forecast weather suggests a substantial storm slab problem could form with new snow before precipitation switches to rain on Tuesday. Fresh accumulations will shed from steep slopes increasingly easily as temperatures rise.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Nov 30th, 2021 4:00PM