Recent strong winds with lots of new snow has heightened the avalanche hazard. This is a good time to avoid avalanche terrain.
Confidence
Moderate - Intensity of incoming weather systems is uncertain
Weather Forecast
Tuesday will be snowy with accumulations near 8cm. Winds will continue to be strong from the SW. Temperatures are expected to be mild for a couple of days with a high of -1 C tomorrow and then freezing levels rising to 2600m on Wednesday with rain/snow in the forecast.
Avalanche Summary
Naturally triggered slab avalanche activity up to size 2.5 has occurred in the past 24 hours. Most of these slides occurred on N and E aspects in alpine terrain, but in some areas the slides have run to the end of their run-outs at lower elevations. Loose dry avalanches up to size 2.0 have also been observed in steep Alpine terrain.
Snowpack Summary
An average of 30cm of new snow fell overnight at Treeline overnight. This snowfall was coupled with strong to extreme SW winds which has led to widespread wind slab formation in lee and cross-loaded features at Treeline and Alpine elevations. Most windward aspects have been stripped down to bare rock. Natural avalanche activity is ongoing (see avalanche activity discussion below) and conditions are ripe for human-triggering. The Halloween crust is now buried up to 80cm at 2400m and has shown signs of facetting. Recent snowpack tests show a failure immediately underneath the crust, that will be something to watch in the weeks to come.
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.