Avalanche Forecast

Moderate - Uncertainty is due to the limited number of field observations. Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

  

SATURDAY NIGHT: Partly cloudy / Strong, west ridgetop wind / alpine low temperature -14 / Freezing level valley bottom.

SUNDAY: Mostly cloudy / Extreme, west ridgetop wind / alpine high temperature -7 / Freezing level valley bottom.

MONDAY: Cloudy with isolated flurries; 0-3 cm. / Extreme, west ridgetop wind / alpine high temperature -6 / Freezing level 1300 m.

TUESDAY: Flurries; 3-5 cm. / Extreme, southwest ridgetop wind / alpine high temperature -3 / Freezing level 1700 m.

A large (size three) cornice triggered persistent slab avalanche was reported on a large south facing alpine slope in the Crowsnest Pass area on Thursday. This ia an example of the "low probability; high consequence" scenario that persistent slab problems often create. MIN report HERE.

Lingering wind slabs formed by recent snow and wind remain possible to human trigger in isolated areas. The upper snowpack consists of several layers of old wind slabs, while the lower snowpack consists of decomposing crusts and weak faceted snow. In the Elk Valley a decomposing surface hoar layer can be found around one of these crusts 50-100 cm below the surface. Avalanche activity on these layers in the lower snowpack have been sporadic, mostly occurring during natural avalanche cycles. However, this kind of snowpack structure is always a concern for human triggering; especially on steep, rocky slopes with a shallow or thin to thick snowpack.

• Be carefull around freshly wind loaded features.
• Be aware of the potential for large avalanches due to the presence of buried weak layers.
• Avoid exposure to slopes that have cornices overhead.
• Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.