Fridays storm totals are expected to vary greatly across the region. Pay close attention to how much snow falls in your riding area as snowfall amounts and warming will drive the Avalanche Danger on Saturday.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
The region may see 10-20cm of new snow on Friday night with extreme southwest winds. On Saturday morning expect overcast skies and lingering flurries with the possibility of sunny breaks in the afternoon. Another system will bring in up to 20cm of new snow and strong southerly winds between Saturday night and Sunday. On Monday a clearing trend is expected. The freezing level should hover around 1500m for most of the forecast period although there may be a brief spike to about 2000m on Saturday afternoon.
Avalanche Summary
Artificially and naturally triggered storm slab avalanches continue to be reported. Of note, a size 2 storm slab avalanche was remotely triggered on a north-facing treeline feature from a distance of 150m in the Coquihalla area. Additionally, a skier was caught in a size 2 storm slab avalanche on a northwest-facing treeline slope in the Duffey lake area. The individual was not injured in the slide. These avalanches, which occurred on Wednesday, highlight the potentially touchy conditions in some areas. An isolated, yet destructive size 3 natural persistent slab avalanche was reported this week in the South Chilcotin area north of Goldbridge. The avalanche failed on surface hoar buried in early February. Cornices are large and fragile, and may also fail under the weight of a person.
Snowpack Summary
Continued moderate snowfall and extreme southerly winds have formed reactive storm slabs on lee and cross-loaded alpine and treeline features. The upper snowpack sits above a crust that was reported on all aspects and elevations with isolated pockets of surface hoar in high north facing terrain that stayed cool prior to the storm. The mid and lower snowpack are generally well settled. That said, a layer of surface hoar buried at the beginning of February is a concern in the South Chilcotin area and can be found about 80cm below the surface. Although this layer is isolated, it has been responsible for destructive natural avalanche activity and is worth keeping on your radar if you're headed to the north of the region.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.