Winter has arrived and it's time to switch on the "avalanche brain". Ice climbers need to be aware of overhead terrain and be mindful of exposure to terrain traps and cliffs. Carry avalanche rescue gear and know how to use it.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
A series of storms will roll through the area over the next few days with brief clearing periods in between. Snowfall amounts could reach 10 to 15cm by Wednesday, with periodically strong winds.
Avalanche Summary
Loose dry avalanches up to size 1.5 associated the most recent snow have occurred over the past 24 hours. Previous slab avalanche activity has occurred on steep lee aspects in the alpine. Ice climbing parties have been surprised and had close calls in a couple of locations.
Snowpack Summary
It is early season and field observations are very limited. Up to 35cm of snow fell in the last 24hrs now putting many alpine areas above the necessary threshold for avalanche activity. Winds during the recent storm have been generally light, but some localized wind slab development is present. Previously formed hard wind slabs are found in isolated terrain at ridge-top on lee and cross-loaded features.
Problems
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.
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.