Avalanche Forecast

Tuesday will be mainly cloudy with very light flurries and light to moderate SW winds. Temperatures should be in the -8 range before beginning to cool on Christmas Day with a few sunny breaks.

The large scale and destructive avalanche cycle is on-going with some slides reaching the end of their historic run-outs. Slides up to size 3.5 have been observed in the past few days. Ski cutting at lower elevations today produced full-depth avalanches with the entire recent storm snow layer failing on the basal weaknesses.

Another 5 to 8cm of snow fell last night and light snowfall continued through the day. Recent storm snow totals at Treeline are near 100cm. Unfortunately, all this snow sits over a very weak basal layering of facets and crusts. In the Alpine and open areas at Treeline persistent SW winds continue to build wind slabs in lee and cross-loaded terrain. All of this recent snow overlying the weak base has led to a large scale natural avalanche cycle that is still on-going. Natural avalanches are running far and fast and in some cases are reaching the end of their historic run-outs. Ski cutting in steeper terrain below treeline produces full depth avalanches, and very little terrain over 25 degrees is not at risk of being triggered.

• Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
• The trees are not a safe haven, travel at treeline requires expert knowledge and diligence.
• Avoid lee and cross-loaded terrain.