Choose sheltered terrain and use extra caution around ridgetops. Unsettled weather continues to build windslabs. Avalanches can be triggered by the weight of a rider, especially where windslabs are fresh.
Expect most wind loading to be found on east facing slopes (lee to west/southwest winds).
Wind loading may sit over a crust on south facing slopes, or a buried surface hoar in sheltered treeline terrain. Likelihood of human triggering is higher in these features.
TUESDAY NIGHT: Cloudy. 0-5 cm of snow expected. Light to moderate southwest ridgetop winds, trending to strong in the high alpine. Freezing level around 1000 m, alpine low around -5 °C.
WEDNESDAY: Cloudy. Isolated flurries over the day with moderate southwest ridgetop winds, and periods of extreme in the high alpine. Freezing level around 1000 m. Alpine high around -4 °C.
THURSDAY: Mostly cloudy. 5-10 cm of snow expected overnight, and another 0-5 through the day. Moderate to strong southwest ridgetop winds. Freezing level near valley bottom in the morning, rising back to around 1000 m through the day.
FRIDAY: Partly cloudy with scattered flurries. Moderate to strong south ridgetop winds. Freezing level at valley bottom in the morning, rising to around 1000 m in the afternoon.
On Tuesday, small, natural windslab avalanches were reported, as moderate winds continued to move snow.
On Monday, north of Smithers, a naturally triggered size 1.5 windslab avalanche was reported on a steep, northeast facing, treeline feature.
Human triggered wind slab activity continued on Sunday, to size 1 in wind loaded features. Sluffing was observed out of steep and sheltered terrain features.
The late February surface hoar has shown reactivity in recent snowpack tests, and avalanche activity over the last 3 days. A remote size 1.5 was triggered on a northeast aspect at 1450 m. A MIN report describes a size 2 slab avalanche triggered by a snowmobile on a southeast facing alpine slope from Saturday. This layer is most likely to be triggered where winds are loading sheltered open slopes at treeline.
15-25 cm of storm snow is being redistributed into wind loaded pockets by strong southwest winds.
Around 30-40 cm deep, a surface hoar layer buried in late February is preserved in wind sheltered features at treeline and low alpine elevations. On sun affected aspects, this interface exists as a crust. This layer has shown to be reactive in snowpack tests and recent avalanche observations.
The thick mid-February crust is now buried 50-70 cm deep. These layers are unlikely to be human triggered, but possible to trigger with very large loads such as avalanches in motion or cornice falls.
The lower snowpack is well protected by the mid-February crust, and triggering avalanches below this layer is unlikely at this time.
