Avalanche Forecast

A large (size 2) naturally-triggered avalanche was observed along the highway corridor between White Pass and Skagway on Saturday.

We suspect a widespread natural avalanche cycle is ongoing across the region.

Around 25 cm of storm snow fell overnight Friday, and a further 10-30 cm of snow or rain is set to fall by the end of the day Sunday. With forecast strong to extreme alpine winds this new snow will form reactive storm slabs, especially on lee north and east slopes.

The field team has found a buried weak layer of surface hoar and facets 45-70 cm below the surface. While triggering this layer is unlikely, there is potential for smaller avalanches to overload this layer triggering a larger step-down avalanche.

The overall midpack is generally settled and strong, with the average snowpack depth at treeline around 160 cm.

Saturday Night

Cloudy with 10-20 cm of new snow/moderate to heavy rain, south alpine wind 70 km/h, treeline temperature -1°C, freezing levels rising to 1000 m

Sunday

Cloudy with 10-20 cm of new snow/moderate to heavy rain, south alpine wind 60 km/h, treeline temperature 0°C, freezing levels 1000 m.

Monday

Cloudy with 15-25 cm of new snow / moderate to heavy rain, southeast alpine wind 80-90 km/h, treeline temperature 1°C, freezing level 1500 m.

Tuesday

Cloudy with 5-15 cm of new snow, south alpine wind 40-50 km/h, treeline temperature -4°C and freezing levels dropping back to 400 m.

More details can be found in the Mountain Weather Forecast.

• Use increased caution at all elevations. Storm snow is forming touchy slabs.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.