Avalanche Forecast

No significant avalanche activity has been reported this week, but looking forward we expect natural avalanches to occur during periods of intense precipitation and wind-loading over the next few days.

Heavy snowfall accumulations are likely above 1000 m for the next few days. Rain will soak the snowpack at lower elevations. Avalanches during this period could run on a crust layer that was 20 to 30 cm deep before the storm. Snowpack depths at treeline are roughly 100 cm, while most below treeline terrain is below the threshold depth for avalanches, except for isolated smooth features.

Thursday night

A strong low pressure system brings heavy precipitation that peaks in intensity around midnight. Snow accumulations above 800 m range from 15 to 40 cm, with the greatest accumulations on the western side of the island. Extreme southeast wind with gusts exceeding 100 km/h. Freezing level will be around 1200 m resulting in a mix of precipitation types at treeline.

Thursday

A lull between storms in the morning before another storm arrives in the afternoon, bringing 10 to 20 mm of precipitation by 4 pm. Wet snow is expected above 800 m as freezing levels hover around 1100 m. Extreme southeast wind continues, with gusts in the 70 to 100 km/h range.

Another 15 to 30 mm of mixed precipitation by the late morning, then clearing in the afternoon, 30 to 50 km/h wind from the southeast and freezing level around 1100 m.

5 to 15 mm of precipitation with freezing level around 1000 m and 50 to 80 km/h wind from the southeast.

More details can be found in the Mountain Weather Forecast.

• Minimize exposure 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.
• As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
• Loose avalanches may start small but they can grow and push you into dangerous terrain.