Northwest Coastal

New snow, wind and rising freezing levels will increase hazard ratings for Wednesday. Choose conservative terrain and avoid exposure to overhead avalanche hazard. The potential for large avalanches to run long distances exists.

Moderate - Forecast snowfall amounts are uncertain

TONIGHT: Snow. Accumulation 10-15 cm. Ridge wind moderate, southwest. Temperature near 0. Freezing level 1200 m.WEDNESDAY: Snow. Accumulation 20-30 cm. Ridge wind moderate, southwest. Temperature near 0. Freezing level 1400 m.THURSDAY: Mostly cloudy, light flurries. Accumulation 2-4 cm. Ridge wind light, north. Temperature -6. Freezing level 500 m.FRIDAY: Mostly sunny. Ridge wind light, northeast. Temperature -10. Freezing level valley bottom.

Monday evidence of a natural avalanche cycle from size 2.5 - 3.5 was reported on north to south aspects between 1000-1700 m, west of Terrace, with several persistent slabs suspected to have failed on the mid or early January layers during the height of the weekend's storm.Sunday north of Meziadin Junction 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.On Saturday wind and storm slab avalanches failed naturally to size 2 on a variety of aspects in both alpine and treeline elevation bands. A natural size 3 persistent slab avalanche was observed on a steep north facing alpine feature with a crown up to 100 cm in depth, which suggests the mid-January interface was involved. A another very large avalanche (size 3.5) was reported from an unknown aspect/elevation. Late last week natural avalanche activity producing several 30 cm thick slabs in the latest snow was reported as well as lA large (size 3) storm slab avalanche was reported on a east aspect east of Terrace.

Approximately 20-25 cm of new snow since Sunday morning brings settled storm snow accumulations to 50-80 cm over the past week. A freezing rain crust, 5-20 cm thick, was buried early February and can be found 10-40 cm below the surface on all aspects up to 1400 m. A weak layer buried  in mid-January is 100-140 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 treeline 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 may be triggerable from shallow spots.