Regions
Northwest Coastal.
Lingering storm instabilities remain a concern. If you are out for a holiday ski or snowmobile, please consider sending us your observations or posting to our website.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
The next storm system is expected to reach the North Coast on Friday afternoon. 2-4mm of precipitation are expected during the day on Friday with freezing levels reaching 700-1000m and alpine winds increasing to strong from the west. On Friday night/Saturday, 10-20mm of precipitation are expected with freezing levels reaching around 700m and moderate westerly winds in the alpine. Sunday should be mostly sunny and dry with freezing levels around valley bottom.
Avalanche Summary
A report from Wednesday of natural avalanches up to size 2 from steep terrain features at treeline and the upper part of below-treeline. Explosive control on Wednesday produced storm slab and wind slabs up to size 2.5. Most of the activity was on north through east aspects. On Tuesday, natural avalanches up to size 2 were reported from wind loaded areas of the alpine. Natural activity is not expected on Friday but skier triggered slabs remain a concern.
Snowpack Summary
Over 1m of snow fell in the last week. This snow sits on the mid-December rain crust which extends up to about 1400m elevation. At higher elevations this snow sits on heavily wind effected surfaces. Strong SW winds have created wind slabs and cornices which may be a lingering concern. The mid and lower snowpack contains some old crust layers but these layers appear to be well bonded.
Problems
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.