Watch for areas that have recently been affected by the wind. Wind slabs are expected to be lingering in leeward terrain features.
Confidence
Moderate - Wind speed and direction is uncertain
Weather Forecast
Sunny conditions are expected on Wednesday with treeline temperatures around -15C and light northerly wind in the alpine. Sunny conditions continue for Thursday and Friday with treeline temperatures remaining around -15C during the afternoon and light to moderate alpine wind from the northwest.
Avalanche Summary
On Tuesday, explosives triggered one size 1.5 storm slab on a northeast aspects at 2100 m elevation which was 15-20 cm thick. On Monday, several natural storm slab avalanches up to size 2 were observed on a variety of aspects. Ski cutting also produced several storm slab avalanches up to size 1.5. These slabs were typically 15-20 cm thick and were reported to be very reactive in gulley features.On Wednesday, recently formed wind slabs may still be reactive to human triggering. With the winds recently switching directions, wind slabs should be expected on a variety of aspects.
Snowpack Summary
15-20 cm of new snow has buried a variable snow surface which consists of wind scoured surfaces or old wind slabs in exposed terrain, surface hoar up to 20 mm in sheltered terrain, and/or widespread faceted old snow. Recent moderate winds from a variety of directions is expected to have redistributed some of this new snow in wind exposed terrain. Deeper in the snowpack, the mid-December persistent weak facet layer has been more prominent and reactive in the Corbin area than areas closer to Fernie. The layer is generally considered dormant right now but may wake up during the next storm or period of warming.
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.