Strong winds are creating reactive slabs at higher elevations. Human triggered avalanches will remain likely in wind-loaded areas. Choose conservative terrain and be aware of overhead hazard, especially on sunny aspects.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain on Tuesday
Weather Forecast
A proper storm arrives on Tuesday bringing significant snowfall. MONDAY: Increasing cloud in the afternoon. Ridge wind strong from the northwest. Temperature -6. Freezing level valley bottom with an above freezing layer between 1400m and 1900m.TUESDAY: Snow (15-30cm). Ridge wind strong, southwest. Temperature near 0. Freezing level 500 m.WEDNESDAY: Cloudy with sunny breaks. Ridge wind moderate to strong from the north / west. Temperature -5. Freezing level valley bottom.
Avalanche Summary
On Saturday natural wind slab avalanches to size 2 were reported on east aspects (due to north westerly winds) at higher elevations near Terrace. On Friday, explosives control work produced a few size 1.5 storm slab avalanches lower elevations near Terrace. A widespread natural avalanche cycle occurred in the Terrace and Shames areas during Wednesday's storm with reports of numerous storm slab avalanches up to size 2 running far and fast in the new snow at all elevations.A week ago, persistent slab activity was reported north of Meziadin Junction where a natural size 4 and a natural size 3.5 were observed on a southwest and northeast aspect at 1800-2000 m and are suspected to have failed on the mid-January layer.
Snowpack Summary
Strong north west winds picked up on Saturday, redistributing last week's storm snow and creating fresh wind slabs at higher elevations. By Sunday afternoon, winds had shifted to strong from the south east. Wednesday's storm delivered another 30-50 cm of new snow, and a mix of rain and freezing rain for areas west of Terrace. Northern areas have seen about 50-70 cm of recent storm snow.Beneath the storm snow lies a 5-20 cm thick crust that was buried early February and can be found 60-110 cm below the surface on all aspects up to 1400 m. A weak layer buried in mid-January is 120-150 cm below the surface and remains a concern. In most areas this layer is a crust, but it may also be surface hoar in sheltered areas at tree line and below. This layer may remain reactive as it adjusts to the weight of the new snow.In thinner snowpack areas (north and inland), deeper crust / surface hoar layers that were buried in December and early January may still be a concern. They are buried over 150 cm below the surface, but could still be reactive and triggered from shallow spots.
mgrist,
Avalanche Canada
