Avalanche Forecast

On Wednesday there was a report of a size to cornice triggered persistent slab avalanche running in steep alpine terrain in the southeast portion of the region. There was also a report of a size 2 persistent slab avalanche on a west aspect at 1700 m on Tuesday. A very large (size 3) persistent slab avalanche was remotely triggered on Sunday. This avalanche failed on a 50 cm deep facet layer and released on a northeast aspect at 1900 m. We continue to get evidence that this persistent slab can be still be triggered by riders in specific areas.

Recent moderate to strong southerly wind has formed wind slabs in lee terrain features near ridges.

Several persistent weak layers may be found in the top meter of the snowpack. These include a surface hoar layer buried on Dec 28 found 40 to 60 cm deep and a facet layer buried on Dec 23 found 60 to 100 cm deep. In alpine terrain, triggering one of these layers is most likely on steep rocky slopes where they present as facets. In treeline terrain, the layers are most likely triggered on steep slopes in open trees where they present as preserved surface hoar.

Thursday Night

Cloudy periods with isolated flurries. Light to moderate southerly wind. Treeline high temperatures around -6.

Friday

Mainly cloudy with scattered flurries, accumulation 3-5cm. Light to moderate south wind. Treeline high temperatures around -4.

Saturday

Mainly cloudy with flurries. Moderate to strong southwest winds. Treeline high temperatures around -3.

Sunday

Cloudy with sunny periods. Light south wind. Treeline high temperatures around -4.

More details can be found in the Mountain Weather Forecast.

• Be especially cautious as you transition into wind affected terrain.
• Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
• Use conservative route selection and resist venturing out into complex terrain.
• Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.