Aoraki/Mt Cook — Avalanche Forecast

A skier accidently triggered a size 1.5 windslab in the upper jollie valley on Tuesday. It was in freshly loaded snow as the NW wind picked up. Several storm slabs were observed to have run after Sundays snowfall, up to around size 2. Extensive roller balling was observed in warming on Monday afternoon. ForecastRain developing in the morning, heavier and more persistent in the afternoon with snow lowering to 2000 metres.Wind at 1000 metresNortheasterly 45 km/h, rising to gale 75 km/h in the morning.Wind at 2000 metresNortherly gale 80 km/h.Wind at 3000 metresNortherly gale 75 km/h, rising to severe gale 100 km/h for a time in the morning and afternoon.Freezing level1800 metres, lifting to 2300 metres in the afternoon.Issued: 12:32pm Tue 11 Aug Not much of a sliding danger at present. Snow is about to get wet below 2000m with incoming rain.

 Up to 50cm of snow fell in the north and west of the region over the weekend, tapering to the south and east. Winds were variable, and generally light. The new snow has bonded well to the older surface and warm temperatures on Monday left surfaces moist up to around 1500m, with extensive roller balling. Fresh reactive windslab was observed to have formed on SE aspects on Tuesday as NW winds increased. Windslab risks will increase over the next 24 hours as a frontal system approaches.