Avalanche Forecast

Moderate - Uncertainty is due to difficult to forecast freezing levels. Uncertainty is due to how buried persistent weak layers will react with the forecast incoming weather.

Friday night: Cloudy, 15-25 cm of snow, transitioning to rain below about 1800 m, moderate to strong southwest winds, alpine temperatures approaching 0 C as freezing levels may reach 2000 meters overnight.

Saturday: Cloudy, 10-15 cm of snow, moderate to strong southwest winds shifting to northwest and easing, alpine temperatures dropping to -4 as freezing levels fall from 1900 m to valley bottom over the day.

Sunday: A mix of sun and cloud, isolated flurries with a trace of new snow, light southwest winds, alpine high temperatures around -5 C.

Monday: Cloudy with periods of sun, light northwest winds, alpine high temperature -6 C. 

Due to continuous stormy weather, there have been daily avalanches reported in the region. Most of these have been storm and wind slab avalanches, on all aspects, at all elevations. They have been triggered by humans, explosives, and naturally.

Over the last week, there have been two notable natural avalanches reported in the south of the region. These were large (size 2.5) persistent slab avalanches breaking 200 cm deep on both northeast and northwest slopes above 2300 m. These avalanches indicate that a deeper instability may become reactive with additional loading. Touchy storm slab avalanches or cornice fall may have the potential to step-down to this layer. 

20-35 cm of snow fell at higher elevations on Friday. By Saturday afternoon, an additional 25-40 cm is expected to accumulate above 1800 m. Forecast strong winds and warm temperatures will speed up slab formation as new snow accumulates as well as contribute to rapid cornice growth. A large, natural avalanche cycle is expected. Rain is forecast to saturate snow surfaces up to 1800 meters, triggering wet loose avalanches. The hazard from wet loose avalanches will decrease as temperatures cool throughout the day on Saturday.

The mid and lower snowpack is generally well settled and strong, however, there is a weak layer of surface hoar currently buried 90 to 170 cm deep. This layer has recently shown signs of instability in the region. New snow, rain, and warming will collectively add considerable strain to this weak layer. The potential for this persistent slab problem to fail naturally and produce large, destructive avalanches will increase during the storm.

• Avoid exposure to overhead avalanche terrain during periods of heavy loading from new snow, wind or rain.
• Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
• If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.
• A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.