Regions
South Coast Inland.
Watch for lingering wind slabs in high north facing terrain and loose sluffing on steep sun exposed slopes.
Weather Forecast
A mix of sun and cloud is expected on Wednesday with the possibility of lingering flurries. Alpine wind is forecast to be light to moderate from the west and treeline temperatures are expected to be around -10C. Similar conditions are expected for Thursday and Friday with mostly sunny skies, light alpine wind, and treeline temperatures remaining around -10C.
Avalanche Summary
On Monday, natural sluffing was observed from steep sun exposed slopes. A small natural cornice fall was also observed from a northeast aspect at 2150 m. No new avalanches were reported on Saturday or Sunday. On Friday, a size 3 persistent slab avalanche was observed up the Hurley at treeline elevation and likely failed on the weak layer from early February.On Wednesday, lingering wind slabs are the main concern. Look for these in immediately leeward features on northerly aspects in exposed terrain. Sluffing from steep sun exposed slopes is also possible during the heat of the afternoon.
Snowpack Summary
At higher elevations, 10-30 cm of recent snow overlies the widespread mid-February crust layer. Recent reports suggest this snow is well bonded to the crust. Wind slabs and cornices were previously being reported in high north facing alpine terrain aspects but these are expected to have gained considerable strength over the past couple days of colder temperatures. In the north of the region, a facet/surface hoar layer from early February down 60-100 cm was recently reactive in snowpack tests but would be very difficult to trigger without something heavy like a cornice fall or smaller avalanche stepping down. In the south of the region, the mid and lower snowpack are well settled and strong.
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.
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.