We are expecting some new snow over the next few days but models call from 5-20cm. If 20cm arrives, expect Alpine areas to approach considerable hazard.
Weather Forecast
Models differ on amounts but it looks as if we will get between 10-15 cm of snow over the next 36hrs. Winds are forecast to remain moderate before the pelting winds come later in the week. Watch for windslabs to continue to build and if the forecast amounts are at the higher end of what is forecast we may even see the danger in Alpine terrain start to approach considerable.
Avalanche Summary
There have been a few reports of smaller avalanches in Alpine features along ridgelines and in morainal terrain. Ice climbing we have noticed a few pockets of windslabs along routes.
Snowpack Summary
A few cms of new snow has fallen over the past 36hrs but not enough to cause a significant change in overall avalanche danger. Windslabs can be found along ridgelines and in gullied terrain in Alpine areas and isolated features at treeline that may be reactive to a skiers weight. Below treeline, most areas are still below the threshold values for avalanches to occur. Our main layer in the snowpack at this time is the Halloween crust down 20-50cm. We have limited field observations on this crust at this time due to rugged travel at lower elevations. Ice climbers need to be aware of slabs in gullied terrain and at the base of routes.
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.