Avalanche Forecast

Moderate -

Monday: Mainly cloudy with isolated flurries and a trace to 5 cm of new snow. Light southerly winds. Alpine temperatures of -12. Tuesday: Mainly cloudy with isolated flurries and a trace of new snow. Light to moderate southeast winds. Alpine temperatures of -13. Wednesday: Mainly cloudy with scattered flurries and up to 5 cm of new snow. Light variable winds. Alpine temperatures of -14.

Reports from Saturday include numerous observations of storm slabs running Size 1.5-2.5 on all aspects, with several running to Size 3. Crown fractures averaged about 40 cm but were noted as deep as 80 cm in presumably wind loaded areas. All of these ran naturally. Backcountry users in the Cariboos should be aware that many parts of the region have a similar snowpack structure to the Clemina Creek area, where two size 2 snowmobile triggered persistent slab avalanches were reported last Saturday (see MIN report here). Last Monday, another size 2 persistent slab avalanche was accidentally triggered by a skier northwest of Valemount. Triggering a large deep persistent slab avalanche is an ongoing low probability - high consequence problem that demands an extra cautious approach to terrain selection in our region. See here for a list of recent near misses in the region.Looking forward, expect a decline in natural avalanche activity while human triggering potential to the full depth of our recent snow accumulation persists for a few more days. Backcountry users should also keep in mind the ongoing potential for smaller avalanches to trigger deep instabilities.

Just under a week of stormy weather has blanketed the region in 45-70 cm of new snow. The snowfall was accompanied by moderate to strong southerly winds, which promoted the formation of touchy storm slabs at upper elevations. The new snow has buried faceted surface snow, thin sun crust on steep solar aspects, as well as surface hoar reported in sheltered areas in some parts of the region previous to the storm. About 75-100 cm below the surface you'll likely find the mid-February interface, which is composed of a thick rain crust up to about 1700 m, sun crusts on steep solar aspects, and spotty surface hoar on shaded aspects. Recent reports have suggested greater reactivity on this layer at lower elevations where the rain crust is more prominent. Professionals in the region have also warned that a 'threshold load' has been reached above this interface, particularly where it presents as a crust. Some lingering surface hoar layers from January are now down a metre or slightly more and the weak mid-December facets are down about 1.5 metres. These deep persistent weaknesses still have the potential to react to human triggers or smaller storm slab avalanches.