Avalanche Danger is slowly trending down. The snowpack has seen a lot of change in the last few days, and it may need another day to adjust. Conservative terrain choices are recommended.
Confidence
Moderate - Freezing levels are uncertain on Saturday
Weather Forecast
Overnight: Cloud developing overnight that will keep the freezing level close to 2000 metres. Saturday: Overcast with flurries or light snow combined with moderate westerly winds and daytime freezing around 2100 metres. Sunday: A cooler day with a mix of sun and cloud. Moderate westerly winds and freezing around 1500 metres. Monday: Re-freeze to valley bottom expected. Chance of snow developing from the northeast.
Avalanche Summary
Numerous storm slab avalanches up to size 2.5 reported from explosives control on Friday, as well as loose wet avalanches released by ski cuts up to size 1.5. Numerous storm slab and loose wet avalanches were reported from the Fernie area on Thursday. One natural cornice fall was size 3.0, and pulled a storm slab from the slope below. There is concern for storm slabs to continue to be reactive to human triggering if there is little or no re-freeze before another warm day on Saturday.
Snowpack Summary
Storm slabs in the alpine received a big punch of solar radiation on Friday. Sheltered slopes may continue to be dry and may not be well bonded to the old surface. At treeline and below the snow is moist or wet, and may not get a good re-freeze overnight before another forecast warm day with high freezing levels. The deep persistent weak layer of facets and crust that was buried early in the winter may "wake-up" due to this prolonged warming and recent loading. This deep problem is difficult to forecast, and the best strategy may be to avoid large terrain features until the snowpack cools and adjusts to the recent inputs (ie loading, sun, wind, and temperature fluctuations).
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 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.
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.