With rain falling on Tuesday and Wednesday up to 1900m saturating the snow pack and cold temperatures forecast for the day there will a high sliding hazard at mid and lower elevations. Carry an ice axe and crampons. Above 1900m up to 40cm of snow fell accompanied by winds up to gale strength from the NW - there may remain isolated pockets of unstable wind slab in steeper terrain.
The combination of periods of fresh snowfall and gale force winds from the NW 1/4 plus existing large amounts of loose dry snow available for transport has created a windslab hazard. Though this seems to be settling, unstable pockets slopes lee to the NW may exist on specific terrain features at higher elevations. Fresh snow and wind from the south later today may see new pockets of wind slab develop that may become more reactive.
Wet slab and loose wet avalanches have been observed at mid and lower elevations due to the warm wet cycle over the past 72 hours. Above 1900m isolated natural wind slab activity has been observed in pockets of steeper terrain on slopes lee to the west.
If you see any recent avalanche occurrences or have any relevant snowpack information or photos, you can share them via the Public Observations link on the NZAA home page.
Above 1900m: Approximately 15-40cm of new snow fell from Tuesday to Thursday. This snow has largely bonded well to the old snow surface and the upper and mid pack are generally showing settled characteristics as total snow depths have increased and with warmer temperatures recorded. With the very strong winds experienced throughout the winter there is a high degree of spatial variability in the distribution of snow and there are still areas of unusually shallow snowpack at all elevations. The lower part of the snowpack also appears consolidated and unreactive. Large cornices have also formed above 1800m.
Below 1900m rain has saturated the snow pack turning it isothermic. With colder temperatures there is a very slick snow surface.
Caution should still be taken, particularly in steeper, more extreme terrain where unknown weaknesses may exist.
Scattered rain developing in the morning, with snow possible to 400 metres from late afternoon.
Wind at 1000 metres: Light, southeasterly 35 km/h developing in the morning.
Wind at 2000 metres: Southwesterly 30 km/h, turning to southeasterly 30 km/h in the morning, rising to gale 65 km/h in the evening.
Wind at 3000 metres: Westerly 30 km/h, turning to southerly 55 km/h in the afternoon, rising to gale 70 km/h at night.
Freezing level:1800 metres, lowering to 1200 metres in the afternoon, then to 800 metres in the evening.
Rain has fallen to 1900m creating a very slick frozen snow surface which with cold temperatures will present a sliding hazard all day. Take care. An ice axe and crampons could be necessary.
High
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
