As the storm passes, and loading by wind and snow slows, natural avalanche activity will decrease. It will take time, however, for the snowpack to adjust to the new load. You might be all it takes to overload it, with severe consequences.
Weather Forecast
Light flurries, cooling temps and moderate to strong S'ly (N'ly at mountain top) winds are expected today as the storm leaves the region. A brief ridge of high pressure will bring a mix of sun and cloud and light winds for Monday. S'ly winds will increase again as another low pressure system arrives overnight on Monday. With light snow on Tues.
Snowpack Summary
60cm of heavy, moist snow fell in 48hrs and rapidly loaded the Feb 12 surface hoar/crust layer down ~1m. The surface snow is wet to 1400m and moist to at least 1900m. In the alpine, S'ly winds are transporting snow, rapidly loading slopes and forming new windslabs. Cooling temps will help to start strengthening the snowpack, but it will take time.
Avalanche Summary
Natural avalanche activity continued yesterday. 15 size 2-3 avalanches were observed along the highway, with moist debris and running well into the avalanche fans. The large avalanche cycle during the storm (see yesterdays bulletin) occurred on the storm interface and Feb 12 layer. None appear to have stepped down to deeper layers.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.