New snow and wind are expected. Windslab will be building over potentially 'weak' snow.
Surface hoar and weak crystal types have grown during the recent cold, clear weather.
It would be a good plan to wait the storm out before pushing into backcounty terrain.
Surface hoar and weak faceted snow have been observed on shady aspects. SE snowfall earlier last week has loaded up NW aspects, so when the N/NW wind ramps up there is plenty of snow available to transport onto SE facing slopes. With the new snowfall forecast as well-some models predict 10-15cm over late Monday, the recipe is there for a rapid increase in avalanche danger.
The freezing level is a little uncertain. There maybe rain below around 1500m. This could quickly destabilise recent snowfall.
A widespread cycle of loose wet avalanching took place earlier in the week up to size 1.
Approximately 90cm of new snow fell in the Ohau area over the early half of the week at 1800m, tapering to around 45cm at 1500m. Many slopes are only just getting to threshold for avalanching and many rocks will be lurking. Two rime crusts are buried around 20cm -30 cm below surface, but the depth is variable depending on local wind effect. Direct solar slopes will have some degree of melt freeze crust, and faceting has been observed below this crust, while surface hoar has been developing on shady slopes. Incoming NW winds and forecast snowfall over the first few days of the new week will lead to a rising avalanche hazard.
Strengthening NW winds and developing snowfall through Monday afternoon, with rain below around 1400m.
Probably not much of sliding hazard at present, though there maybe firm snow exposed at ridgelines and solar slopes will have a melt freeze crust.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
