Ohau
New Zealand · New Zealand Avalanche Advisory · part of New Zealand
Forecast issued 21 hours ago · valid to Jul 23
Published by New Zealand Avalanche Advisory
Current forecast
- High Alpine · above 1,800 m
- 1 · Low
- Alpine · 1,200 m–1,800 m
- 1 · Low
- Sub Alpine · below 1,200 m
- 1 · Low
Highlights
Much of the terrain below 2000m is either scoured to bare rock or a very firm wind-packed or rain crusted surface.
Slide for life is as much or more the contingency to prepare for as avalanche right now.
Avalanche problems
Wind Slabs
Unlikely · Size 1
Wind slab danger exists on isolated east to south aspects above 1800 m.
Denser new snow has loaded onto weak layers, but no reactivity has been observed. Warm temperatures have helped the snowpack consolidate and strengthen.
Use caution in steep, wind-loaded terrain where isolated slabs may remain reactive.
Recent Avalanche Activity
14 July – Multiple size 1 loose wet avalanches triggered by a rain-on-snow event were observed from Ohau Ski Field. Cornice failures were also observed along the ridgeline.
A few shallow windslabs failing on either the rain crust or going to ground from several days ago.
Current Snowpack Conditions
Approximately 15–20 cm of new snow fell above 1850 m between 13–14 July, accompanied by severe NW winds that later shifted to the SW. In exposed terrain, the strong winds stripped the new snow back to the ground or to slick rain crusts.
Wind loading created pockets of dense wind slab on east through south aspects in isolated pockets, but can be 30-40cm thick. They so far haven't been reactive to tests.
Below 1850 m, precipitation fell as rain, forming a widespread rain crust on all aspects.
Mountain Weather
Partly cloudy with isolated showers, clearing by afternoon. Moderate westerly winds and a freezing level heading towards 2600m
Sliding Danger
Firm snow conditions are present on west-facing slopes near ridgelines and at lower elevations where a rain crust exists. These hard surfaces may present a sliding hazard, particularly on steep terrain.
This forecaster wore crampons for the whole decent of Mt Sutton to the ski area (a popular off piste ski run) on Sunday, and was very happy to have them.
Forecast Confidence
High
- The snowpack structure is well understood.
- We are confident due to a stable weather pattern.
- We have a good understanding of the snowpack structure and confidence in the weather forecast.
New Zealand Avalanche Advisory (NZ Mountain Safety Council)