The storm has left us with a mix of scoured ridges and wind loaded gullies above 1800m and a slick rain crust below. Those wind loaded slopes could still slide, and firm conditions elsewhere might make them extra enticing.
Look out for ongoing wind loading and if you're skiing the wind-buff, keep it low angle.
Gale SW winds have and will continue to transport large quantities of new snow, creating wind slab on sheltered north, east, and southeast aspects above around 1800m. These slabs may still be reactive on Friday. Look out for signs of recent wind deposition including wind-wave textures on the surface and pillowy drifts of new snow.
Freezing level is rising to 2300m on Friday. Loose wet avalanches are possible on sunny slopes in the afternoon. Watch out for rollerballing or sticky heavy snow as these are signs the snowpack is losing strength.
16 July: A widespread loose avalanche cycle was observed on all aspects below around 2000m. A mix of wind slab and storm slab avalanches were visible along the northern Ben Ohaus and Mueller range, notably:
14 July: size 3 suspected wind slab avalanches were visible from Aoraki Mt Cook Village on SE facing slopes in the Hayter and Stewart Stream drainages off the Divide.
Please let us know via the Public Observations link if you see any slides.
Around 120cm of new snow has fallen around the divide, tapering to around 100cm on the Liebigs, and 25cm in the eastern part of the forecast area above 2000m, with a mix of rain and new snow down to around 1500m. This has been redistributed by gale NW and SW winds leaving deeper drifts in sheltered areas and slick crusts in exposed areas. Below around 1800m the snowpack is capped with a hard rain crust.
Around the divide this sits on a fairly well settled lower snowpack, but away from the divide this new snow sits on a rime crust that was faceting prior to the storm. We need more data to know how that crust facet combination will behave with this new load.
Fine, then a few showers developing in the afternoon.
Wind at 1000 metres: Westerly 35 km/h but 55 km/h in exposed places.
Wind at 2000 metres: Westerly 50 km/h, rising to gale 70 km/h in the afternoon.
Wind at 3000 metres: Southwesterly 55 km/h, rising to gale westerly 75 km/h early afternoon.
Freezing level: 2300 metres.
Exposed areas have been stripped back to a slick crust by strong NW and SW winds. Below 1800m there may be slick rain crusts. Take an ice axe and crampons for any travel above the snowline.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
