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 - Due to the number of field observations
Weather Forecast
Strong northerly winds and sun effect are the main weather factors on Sunday. A proper storm arrives on Tuesday bringing significant snowfall. SUNDAY: Mostly sunny. Ridge wind moderate to strong from the north / east. Temperature -7. Freezing level valley bottom.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 (15-25cm). Ridge wind strong, southwest. Temperature near 0. Freezing level 500 m.
Avalanche Summary
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. Wednesday's storm delivered another 30-50 cm of new snow, and a mix of rain and freezing rain for areas west of Terrace, bringing storm snow totals of over 100 cm in the last 2 weeks for the Terrace area. 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 produced a few human triggered avalanches throughout the region over the past week, and 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
