Regions
Northwest Coastal.
Confidence
Fair - Forecast snowfall amounts are uncertain on Saturday
Weather Forecast
The cold arctic air should begin to be pushed out of the region starting this evening. Strong northeast outflow winds may continue into the evening, and then be replaced with moderate to strong southerly winds by Friday afternoon. Coastal areas may receive 5-10 cm by Friday morning, and a further 10-20 cm during the day on Friday. Inland areas are expected to get about half as much snow during this period. Freezing levels are expected to remain near the valley bottoms in the Smithers area, and may rise to about 700 metres briefly on Friday afternoon near Terrace. Temperatures are expected to rise to about -4.0 at treeline on Friday and then drop slightly to about -7.0 at treeline on Saturday. Strong south-southwest winds on Saturday should continue on Sunday. A series of Pacific frontal systems will continue to bring precipitation over the next few days.
Avalanche Summary
Some natural and cornice triggered avalanches up to size 2.0 have been reported from slopes that were loaded by the recent strong NE winds.
Snowpack Summary
The deep snowpack is considered to be well settled with no persistent layers of concern. Some areas have about 20 cm of dry cold snow above the old storm snow that ended about January 8th. Windslabs that have developed due to strong NE outflow winds have not bonded to this layer. Some areas have developed surface hoar or surface facetting on sheltered slopes in the alpine and at treeline.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.