Avalanche Forecast

SATURDAY NIGHT: Mostly cloudy, moderate south wind, alpine temperatures around -15 C.

SUNDAY: Cloudy with sunny breaks, isolated flurries with a trace of snow, moderate south wind, alpine temperatures around -15 C.

MONDAY: Sunny with a few clouds, light variable wind, alpine temperatures around -12 C. 

TUESDAY: Cloudy, isolated flurries with a trace of snow, light southwest winds, alpine temperatures around -13 C.  

On Thursday, a MIN report in the south of the region detailed a spike in wind speed and a shift in direction to northeast that formed touchy slabs, loaded cornices to their breaking point, and likely initiated a large avalanche in the alpine. 

Last weekend there was a very large (size 3) natural wind slab avalanche on a northeast aspect near Valemount, as well as this neighboring report of a very large (size 2.5-3) natural avalanche on a southeast aspect on Mt. Goslin. A few size 2 avalanches were also reported in the Barkerville area. These included a mix of wind slab and persistent slab avalanches on a 40 cm deep surface hoar layer, mostly on treeline features (see some photos in the MIN reports here, here, and here). One was thought to have been initiated by a machine-triggered cornice fall. 

In the first week of February, there was a flurry of persistent slab avalanche activity on the same surface hoar layer in the riding areas around Valemount and Blue River. Although the likelihood of triggering persistent slab avalanches is decreasing, this weak layer warrants assessment in open, sheltered slopes at treeline where this layer is likely pronounced and preserved.

Winds are forecast to shift to a new direction overnight (southeast) and again tomorrow (south) that may form fresh wind slabs in lee features at upper elevations. Previous winds blew from the east/northeast with enough gusto to move snow and build reactive wind slabs. Watch for these wind slabs in unusual places as tricky cross-loading and reverse-loading continues. 

While wind may be forming slabs in lee features, the upper snowpack is becoming soft and faceted with the cold temperatures. 40-70 cm of snow from February is settling over a reactive weak layer of surface hoar buried in late January. Reactivity on this layer has primarily been observed at treeline and in "treeline-like" features, like cutblocks, that are below treeline. Snowpack test results continue to show instability on this layer, like this MIN report from Allan Creek on Friday. On steep south-facing terrain, this layer may consist of facets on a sun crust.  

Additional weak layers may present in the lower snowpack, but are not a concern in most areas until we see significant snow loading or rapid warming. 

• Recent wind has varied in direction so watch for wind slabs on all aspects.
• Approach lee and cross-loaded slopes with caution.
• Be aware of the potential for large avalanches due to the presence of buried surface hoar.
• Extra caution is needed around cornices under the current conditions.