Avalanche Forecast

WEDNESDAY NIGHT: Cloudy / Moderate, northwest ridgetop wind / alpine low temperature -12 / Freezing level valley bottom.

THURSDAY: Cloudy with isolated flurries; 0-3 cm. / Moderate, northwest ridgetop wind / alpine high temperature -9 / Freezing level valley bottom.

FRIDAY: Cloudy with isolated flurries; 0-3 cm. / Strong, northwest ridgetop wind / alpine high temperature -8 / Freezing level valley bottom.

SATURDAY: Flurries; 3-5 cm. / Light, west ridgetop wind / alpine high temperature -9 / Freezing level valley bottom.

On Tuesday, numerous natural storm slabs up to size 3 and skier triggered up to size 1.5 were reported throughout the region on all aspects and elevations. Here is one excellent example from the Gorge area and another from Corbin Pass.

On Monday, several skier triggered storm slab avalanches up to size 2 on surface hoar were reported in the gorge area and natural avalanches up to size 3.5 were reported just east of the region in glacier national park.

A widespread natural cycle and numerous skier triggered storm slab avalanches up size 2 were reported on all aspects in the Gorge area west of Revelstoke on Sunday. These storm slab avalanches were running on a weak layer of surface hoar that was buried by the recent storm. See one of numerous MIN reports Here.

Touchy storm slabs are sitting on a very weak layer of surface hoar which is likely to be reactive to human triggers. Avalanches may be larger than expected due to the presence of this weak layer.

60-90 cm. of recent snow, warm temperatures, and moderate, southerly winds have formed touchy storm slabs. These storm slabs are sitting on multiple weak layers of surface hoar which have potential to surprise backcountry users by how easily they may be triggered and how wide the slabs propagate across slopes. The first sits below the recent snow and the second is around 10-20 cm. deeper.

A third layer of surface hoar can be found on wind sheltered open slopes at treeline and below down 90-120 cm. in some areas. Large triggers, new snow loads, and/or warm temperatures have the potential to awaken these deeper persistent weak layers.

The lower snowpack is generally well settled and strong. 

• Be aware of the potential for large avalanches due to the presence of buried surface hoar.
• Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
• Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.
• Be careful as you transition into wind affected terrain.
• Be aware of the potential for human triggerable storm slabs at lower elevations, even on small features.