Thursday is forecast to be warm, so expect small loose wet avalanching in whatever new snow has fallen during the storm.
If you're venturing into the north of the forecast area, be wary of wind loaded features as wind slabs at upper elevations could be large enough to bury a person.
Freezing level is forecast to rise to 2400m overnight and lower to 2000m by Thursday afternoon. Combined with some potential sun in the afternoon, this is very likely to kick off a loose wet avalanche cycle, especially on steep slopes above 1700m where new snow has fallen.
Look out for rollerballing or wet, sticky snow as these are clues that the snowpack is losing strength.
Wind slab avalanches are possible on Thursday as gale northwesterly winds shift the new snow. These could be big enough to bury a person in the north of the forecast area where up to 25cm of new snow is forecast. Around Ohau ski area, where roughly 10-15cm of new snow is expected, these should be small.
Wind slabs will be confined to areas where new snow has fallen, so probably above 1800m in the south of the forecast area, and at slightly lower elevations near the Divide where temperatures are forecast to be cooler.
If you're high enough to encounter new snow, avoid loaded terrain features near ridgeline on sheltered E, SE and E facing slopes.
Ohau Ski Patrol reported one small wind slab avalanche from a ski cut at 1880m on a south aspect on the 12th of August.
Roughly 5-10cm of new snow has fallen above 1700m around Ohau Ski Area on Wednesday, with an estimated 10-15cm in the northern part of the forecast area. Below 1700m, this fell as rain. The previous snow surface was already moist up to approximately 2000m, with some dry snow left on shady aspects above 2100m.
The lower pack was a mix of melt freeze crusts on sunny slopes, windscoured crusts in exposed areas, and drifts of firm, windpressed snow. With a thin snowpack in places and some cold nights, faceting has been observed in the lower pack, but so far we're not seeing any weak layers that are causing problems.
About the Divide: Rain, heavy at times with snow to 2000 metres, easing to showers in the morning and clearing at night. Elsewhere: the odd shower, clearing to fine in the afternoon.
Wind at 1000 metres: Northwesterly 50 km/h but gale 80 km/h in exposed places, easing to 35 km/h but 55 km/h in exposed places before dawn, and dying out at night.
Wind at 2000 metres: Gale northwesterly 75 km/h, easing to 50 km/h in the morning, and dying out in the evening.
Freezing level: 2400 metres, but 2000 metres about the Divide, becoming 2000 metres elsewhere in the afternoon.
New snow at higher elevations and moist snow at lower elevations should make for soft travel conditions with minimal sliding hazard.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
