Continued snowfall and strong winds will keep the avalanche hazard elevated through the forecast period
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
Tuesday: Flurries with periods of snow, accumulation 15-20cm / Moderate to strong southwest wind / Alpine temperature 1Wednesday: Snow, accumulation 10-20cm / Moderate to strong southwest wind / Alpine temperature -1Thursday: Snow, accumulation 20-30cm / Moderate to strong southwest wind / Alpine temperature -0
Avalanche Summary
Expect avalanche activity to stay on the rise with new snowfall accumulating Sunday night into Monday combined with moderate wind and warming temperatures. There was natural avalanche cycle Sunday night into Monday morning with avalanche releases up to size 2. Reports indicated that avalanches to size 1.5 were being easily triggered with ski cuts.
Snowpack Summary
Up to 50cm new moist or wet new snow overlies the variable old snow surface from late last week, which includes well settled snow on southerly aspects, loose snow on shaded aspects, isolated pockets of surface hoar, and sun crusts on steep southerly aspects. With the potential for buried surface hoar means storm snow weaknesses from this latest storm will take longer than normal to stabilize. An old rain crust is reported to be down 150 cm in the North Shore mountains. This layer is still failing on snowpack tests, but is likely difficult to trigger in most places now.
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.