Avalanche Forecast

The ridge of high pressure brings two more days of dry and sunny conditions before the next storm system arrives Saturday evening bringing snowfall for Sunday. 

Thursday Night: Mainly clear with valley cloud, light SW wind, treeline temperature around -10 °C.

Friday: Sunny with valley cloud, light SW wind, treeline high around -4 °C.

Saturday: Increasing cloud cover, moderate to strong SW wind, treeline high around -4 °C.

Saturday night and Sunday: Snowfall 10-15 cm, moderate to strong SW wind, treeline high around -3 °C.

On Wednesday, some natural wind slabs up to size 2 were reported in extreme rocky terrain and solar triggered loose avalanches up to size 2.5 were observed from steep rocky terrain. A size 3 cornice failure was also reported which had occurred a day or two earlier. 

No new avalanches were reported on Tuesday. On Monday, numerous loose snow avalanches (up to size 2) and few wind slabs on cross-loaded features were triggered by strong solar radiation. On Sunday, a snowmobiler accidentally triggered a large wind slab (size 2.5) on a lee alpine slope. The fracture line was up to 1 m deep. 

A deep persistent avalanche problem in the North Columbia forecast region has produced large and notable avalanches last weekend, and the southeast corner of the Cariboos appears to have a similar lingering problem. On Saturday, explosives triggered a 2.5 deep persistent avalanche on a NE aspect at 2100 m south of Valemount.

The snow surface is highly wind affected in exposed terrain and wind slabs are lingering in leeward features. On steep solar aspects and at lower elevations, a melt-freeze crust may be found. In sheltered areas, a new layer of surface hoar is expected to be fairly widespread and some operators reporting it to be as large as 15 mm. 

The upper snowpack contains a few prominent layers but these generally appear to have gone dormant and are not currently creating a problem. A thin crust and a spotty layer of surface hoar buried last week may be found down around 20 cm. A layer of facets and small surface hoar from early January is now down around 60 cm and a thick layer of facets from the end of December is down around 80-100 cm.

The lower snowpack is strong and settled in most parts of the region, except the southernmost part of the region around Blue River where there is a deeply buried crust/facet layer from early December that could be exhibiting similar behavior to the deep persistent slab problem in the neighboring North Columbia region. This layer is most prevalent at below treeline elevations and has been reactive to heavy triggers like smaller wind slab avalanches that step down to this layer. This layer is now considered dormant but could still wake up with storm loading or a major warming event. 

• Carefully evaluate steep lines for wind slabs.
• Wind slabs may be poorly bonded to the underlying crust.
• Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.