We are expecting a significant rise in avalanche danger (if the forecasted snow fall actually arrives!). Very conservative route selection is in order.
Confidence
Low - Intensity of incoming weather systems is uncertain
Weather Forecast
Wednesday will be warm and very windy with a mainly cloudy sky. The big unknown is the amount of snow fall. Some models are calling for almost no snow accumulation, while other models are predicting 15 to 20cm by Wednesday afternoon. Most models agree that Thursday and Friday will be cloudy with only light precipitation.
Avalanche Summary
Two naturally triggered size 2.0 slab avalanches were observed today. One occurred on a West aspect of Mt Engadine in an Alpine feature. The other avalanche occurred at Treeline on a steep North aspect. Both of these avalanches appeared to have failed on the basal facets and ranged between 60 an 80cm deep.
Snowpack Summary
Trace amounts of new snow have fallen in the past 24hrs and very light flurries were falling this afternoon. The snowpack is settling due to the recent warm temperatures. Surface snow was moist on solar aspects up to 2100m and this may extend higher in elevation (this is unconfirmed). Intense snow transport was observed at ridge crest and it is very likely that further wind slab development has occurred in the Alpine. The remainder of the snowpack remains weak and facetted, and it is likely that an avalanche initiating in the upper snowpack will steep down to the basal 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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
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.