Freezing levels are rising on Tuesday and we may see a natural loose wet avalanche cycle. Watch for signs of rollerballing or wet, sticky snow as these area sign the snowpack is losing strength. It's a good time to stick to shady terrain.
The snow on sunny slopes has resisted the warming effects of the sun so far, but this can't last forever. Freezing levels are forecast to rise to 2100m so a natural loose wet cycle is possible on sunny slopes.
These should be small, but pay attention to the terrain above you and watch out for terrain traps where even a small avalanche could have serious consequences.
Wind transport was observed in the southern Ben Ohau range and along the Divide on Monday. Other parts of the forecast area that are similarly exposed to westerly wind may have small pockets of fresh windslab on Tuesday.
Look out for textured or pillow shaped drifts of snow in sheltered east facing slopes near ridgeline above 2000m.
A natural avalanche cycle has taken place. Many size 2-3 slab avalanches were observed to have run probably during the storm. A loose wet cycle was also underway to size 1 as the day warmed up on Sunday.
Around 100cm of new snow has fallen about the Divide since late Thursday and into Friday with 50cm at Mueller hut (1800m elevation), and around 60cm in the Liebig range, around 40cm in the Cass, and 20-30cm in the southern Gammacks above around 1000m. This snow is generally well settled and has dried out on shady slopes after several cold nights, with surface hoar and near surface facets developing. The previous snow surface was a mix of rain crust below 1800m, and wind scoured surfaces in exposed areas and windpressed snow in sheltered areas above 1800m. The lower snowpack is generally well bonded with no major layers of concern.
Mainly fine, some passing cloud.
Wind at 1000 metres: Light, southwesterly 30 km/h developing for a time in the morning.
Wind at 2000 metres: Southwesterly 35 km/h dying out in the afternoon. Northwesterly 30 km/h developing at night.
Wind at 3000 metres: Southwesterly 35 km/h dying out in the afternoon. Northwesterly 30 km/h developing at night.
Freezing level: 1800 metres, lifting to 2100 metres in the morning.
Most slick surfaces have been covered with new snow, but an ice axe and crampons are recommended for travel above 2500m.
High
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
