Regions
Vancouver Island.
Confidence
Moderate - Uncertainty of timing and amounts on Friday.
Travel/Terrain Advice
Be observant of storm snow totals and avoid recently wind loaded slopes and rollovers in the alpine and at treeline and make conservative choices. Conditions will be more dangerous during the peak of the storm and will take some time to settle down. Be aware that even small avalanches may have large consequences if terrain traps are involved. Test low consequence slopes and rolls and take note of the aspect, elevation and terrain characteristics.
Past Weather
Moderate precipitation spread across the forecast region over the past 48 hours. Amounts of 12-40 mm with higher totals on the west coast and central Strathcona Park and lower amounts to the north and east. Winds were generally light (less that 25 km/h) and from the W through SE. Temperatures remained relatively cool and rain was observed only below 800 m.
Avalanche Summary
No new natural activity observed. Several small loose dry avalanches from steep NW treeline terrain were produced with ski cutting on Thursday.
Snowpack Description
Surface - Recent low density storm snow up to 30 cm is evenly distributed across a variety of old surfaces. This snow has shown signs of moderate bonding to previous layers.
Upper - Cold, dry unconsolidated snow is present on all aspects above 800 m. There is a density change within this snow that has exhibited some weak bonding properties just above the December crust.
Mid - Well settled.
Lower - Well settled.
Weather Forecast
Thursday's storm will carry on into Friday and produce light to moderate snowfall into Friday night. By Saturday the low should have moved on and a clearing and warming trend will begin. Expect freezing levels and temperatures at higher elevations to rise to near the tops of the Vancouver Island mountains.
Fri - 10-20 cm of snow. Winds light and variable.
Freezing levels of 300-1000 m
Sat - 0-4 cm of snow. Winds light 5-20 km/h from the northwest.
Freezing levels of 0-1000 m
Sun - 0-3 mm of precipitation. Winds southeast 12-18 km/h.
Freezing levels of 0-2400 m
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.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.