The recent snow has added load to buried weak layers and may still be reactive to human triggers. Conservative terrain selection is recommended.
Weather Forecast
MONDAY NIGHT - Clear with cloudy periods / northeast winds 10-15 km/h / alpine low temperature near -22TUESDAY - A mix of sun and cloud / northeast winds 10-15 km/h / alpine high temperature near -16WEDNESDAY - A mix of sun and cloud / northwest winds 10-15 km/h / alpine high temperature near -17THURSDAY - A mix of sun and cloud with isolated flurries / southwest winds, 15-35 km/h / alpine high temperature near -14
Avalanche Summary
Avalanche activity has slowed down. There were reports of several size 2 explosives triggered avalanches on Sunday. Recent test results suggest that the new snow has not bonded well to a persistent weak layer that was buried in mid-January. This layer is described below in the Snowpack Summary.Many large storm slab avalanches were triggered naturally, by skiers, and by explosives on Saturday. The avalanches likely released at the base of the storm snow as well as within the weak layer of surface hoar buried mid-January.
Snowpack Summary
Around 60 mm of precipitation fell on Friday with a freezing level at 1600 m. Above 1600 m, the precipitation fell as snow, which has been redistributed by northwest winds. It may sit on weak and feathery surface hoar crystals in shaded and sheltered areas. Below 1600 m, the precipitation fell as rain and froze into a melt-freeze crust.The mid-January layer of surface hoar or a crust is buried around 40 to 60 cm. The surface hoar is found on shaded and sheltered slopes and is most prominent between 1600 m and 1900 m. The melt-freeze crust is found on south aspects at all elevations.The remainder of the snowpack is generally well-settled. Thin snowpack areas, such as in the east of the region, may find weak and sugary faceted grains near the base of the snowpack.
Problems
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.