Watch for the new snow to settle into a cohesive slab especially in wind-exposed areas at treeline and above, as well as loose snow releases in steep terrain. A release near the surface has the potential to step down to a deeper weak layer.
Summary
Confidence
Moderate - Freezing levels are uncertain on Saturday
Weather Forecast
FRIDAY: Mostly sunny. Ridge wind light, northeast. Temperature -10. Freezing level valley bottom.SATURDAY: Mostly Sunny. Ridge wind light to moderate, west. Temperature near 0. Freezing level 1600 m.SUNDAY: Mostly sunny. Ridge wind light, northwest. Temperature -10. Freezing level valley bottom.
Avalanche Summary
Numerous natural storm slab avalanches up to size 1 were reported to be running in steep terrain during the storm on Wednesday in the southern part of the region.On Monday evidence of a natural avalanche cycle from size 1.5-2.5 was reported on north through south aspects between 1200-1600 m in the Howson Range failing both in the recent storm snow as well as the deeper mid-December layer. A natural size 2.5 that failed on a deep weak layer of sugary, facets at the base of the snowpack was also reported from the northern part of the region near Ningunsaw.On Saturday a small storm slab was reportedly human triggered on an east facing aspect around 1000 m. And at the start of the storm on Wednesday and Thursday skiers triggered a few small slabs on steep convex rolls.Last week some large (size 2-3) natural persistent slab avalanches in the Howsons, and two large (size 2.5) remotely triggered avalanches north of Kispiox were reported. We have no information from the Smithers area, but suspect a similar deeper weakness could exist there too. Activity on buried weak layers is most suspect during periods of heavy loading or rapid warming, hence it's time to be cautious.
Snowpack Summary
Wednesday's storm delivered between 15-50 cm of new snow totals to 40-100 cm since last Thursday with areas near Smithers and south seeing higher snowfall amounts than areas to the north. This storm snow seems to have formed a well settled upper snowpack. A crust and/or weak feathery surface hoar layer buried in mid-January now lies about 100 cm below the surface. The crust exists well into the alpine and the surface hoar can be found in sheltered areas in the lower alpine and treeline elevations. Recent snowpack tests produced hard, sudden results on weak, sugary snow crystals associated with this crust in the Smithers area, indicating that this is still a layer of concern to watch for.Another two crust / surface hoar layers that were buried in December are now 100-150 cm below the surface. These layers produced sudden results in recent snowpack tests and have been the suspected weak layer in recent large remotely (from a distance) triggered avalanches.
jmcbride,
Avalanche Canada
