Wind slab danger exists due to strong NW winds followed by southerly winds on Thursday and Friday, creating complex wind-loading patterns.
Take time to assess the snowpack and choose your route carefully. Pay particular attention to wind-loaded terrain features such as ridgelines, gullies, and cross-loaded slopes.
Wind slab danger exists on all aspects above 1,500 m due to strong NW winds transporting fresh snow from Thursday into Friday.
On Friday evening, the winds shifted to the south, redistributing the new snow and creating complex wind-loading patterns.
Be cautious around ridgelines, gullies, cross-loaded terrain features, and other wind-loaded areas where reactive wind slabs are most likely to have formed.
Loose wet avalanches are possible on steep sun-exposed slopes as the new snow warms in the sun.
Watch for signs of instability, such as rollerballs or pinwheels, and avoid steep terrain if these are observed.
1 Aug – Two wind slab avalanches on NE and SE aspects above 1800m were triggered with explosives by Ohau Ski Patrol.
20 cm of new snow fell on Thursday and Friday, accompanied by severe NW gale-force winds. The strong winds stripped snow from west-facing slopes and exposed ridge crests.
Wind-loaded pockets have formed on east- to south-facing aspects, where reactive wind slabs are likely to exist.
On Friday afternoon, the winds shifted to the south, redistributing the fresh snow and creating complex wind-loading patterns.
Prior to the storm, the snowpack was generally well settled and stable.
Partly cloudy.
wind at topWesterly 40 km/h rising to 50 km/h early evening.
freezing level
Rising to 2300 metres evening.
Firm snow conditions are present on west-facing slopes near ridgelines and at lower elevations where a rain crust exists. These hard surfaces may present a sliding hazard, particularly on steep terrain and may be cunningly hidden under new snow.
High
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
