New snow to low levels with this current storm. Storm Slab is the main hazard to watch. Take a very cautious approach if travelling in or beneath avalanche terrain.
New snow in the forecast will fall onto a firm surface. If we receive more than 10-15cm of snow then we can expect Storm Slabs to form. These slabs can be tricky to pick but they do tend to settle quickly (48-72hrs) The more snow we receive the larger these will become and if they do get going, are likely to run fast and a long way. Avoid traveling on or below steep (>30 Degree)loaded slopes for the next few days
Wind Slabs are different to Storm Slabs as they are more dense and contain smaller snow particles due to being tossed around and beaten up by the wind. These Wind Slabs will be found mostly on Northern 1/2 aspects near ridge tops and in sheltered zones. Watch for denser, hollow sounding pockets of fresh snow on steep slopes above 30 degrees.
Several Loose Wet avalanches reported in Little Alaska, Mt Olympus and in the Black Range on Pk 1912, 13/08
Snow coverage across the forecast area is super variable. Up to 150cm in some areas down to rime covered rocks. Warm temperatures will have settled the upper pack somewhat, almost creating a spring like snowpack leaving a firm surface after overnight freezes. New snow is likely to fall on this solid surface and will hopefully bond well but we will need to assess once this storm passes through.
Sunday: Showers, falling as snow above 400, clearing about the Mackenzie Basin by afternoon, but persisting as lighter sleety showers in the north. Strong Southerly winds easing a little in the afternoon. Freezing level 700m.
Monday: Fine, but becoming partly cloudy with isolated showers in the evening. Southwest winds increasing in the afternoon. Freezing level 600m rising to 1300m in the morning.
New snow to low levels will significantly reduce the sliding hazard.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
