30 cm of dry new snow in the South of the region may be reverse loaded by building Northerly winds. Watch for pockets of wind slab.
Weather Forecast
Overnight and Friday: A few more cm of snow above 500 metres elevation overnight. Mostly clear with no precipitation during the day. Alpine temperatures around -12 C. Light Northwest winds with strong Northerly outflow winds in large valleys.Saturday: Mix of sun and cloud with light Westerly winds and alpine temperatures around -10 C.Sunday: Mostly cloudy with very light precipitation and light Northwest winds. Alpine temperatures around -17 C.
Avalanche Summary
No new avalanches reported. Expect some sloughing from steep terrain.
Snowpack Summary
Up to 30 cm of new snow has fallen in the past 24 hours on the Southern inland highway passes. This new snow is sitting on a hard melt-freeze crust that developed after the recent record warm alpine temperatures. Warm temperatures at the beginning of the storm have created a good bond between the new snow and the crust; the new snow dried out as temperatures dropped during the storm and created a "right side up" snowpack. Reports from the Coquihalla tell us that there was a narrow band of surface hoar on North aspects below treeline before the new snow arrived. Only about 10 cm has fallen in the North of the region where more widespread surface hoar and near surface facetting was found before the thin layer of cold dry snow arrived. There continues to be a concern for deeply buried layers of weak facetted crystals, this is mostly a concern on slopes with a shallow and variable snowpack in the Duffey Lake and Chilcotin areas.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.