Tongariro
New Zealand · New Zealand Avalanche Advisory · part of New Zealand
Forecast issued yesterday · valid to Jul 21
Published by New Zealand Avalanche Advisory
Current forecast
- High Alpine · above 2,300 m
- 2 · Moderate
- Alpine · 1,800 m–2,300 m
- 1 · Low
- Sub Alpine · below 1,800 m
- 1 · Low
Highlights
Loose wet avalanches are possible on steep slopes with a solar aspect. Loose dry avalanche concern above 2300 metres elevation. For the next 24 hours, the weather is settled, with light winds and fine conditions; however, a few showers are possible.
Avalanche problems
Loose Wet
Possible · Size 1
Loose wet avalanche activity will be possible on slopes being impacted by direct sun. Solar radiation will shock the snow surface. It is essential to stay alert for signs of weakening. Look for increased foot and ski penetration, as well as rollerball activity, which may indicate developing instability.
Loose Dry
Possible · Size 1
Loose dry avalanche activity possible. The upper elevations have received 10 cm of new snow over the previous 24 hours. Loose dry avalanches will be possible in steep terrain features. Problem areas will be all aspects above 2300m over the next 24 hours. Triggering a weakness at the new-old snow interface will be possible.
Recent Avalanche Activity
Multiple size 1 loose wet avalanches on west aspects at around 1800 metres (Turoa yesterday 20072026).
Current Snowpack Conditions
Snowfall accumulation over the past 24 hours was recorded as 10 cm (Turoa, Whakapapa, 2000 metres elevation). A brittle melt-freeze crust formed overnight, capping the new snow below 2000 metres. The new snow was of low density and evenly distributed above 1600 metres elevation. Supporting this new snow lies an older consolidated snowpack. New snow accumulation has most likely occurred on Mt Ngauruhoe and Mt Tongariro, adding to the existing snow cover. The south-west areas of the region have sufficient snow cover in isolated start zones above 1600 metres, mostly on north- and west-facing aspects. South and east aspects remain sparse at lower elevations. In the northern areas, the threshold is at a higher elevation.
Mountain Weather
On the 22nd of July, a few showers, clearing to fine in the morning. The winds are light to moderate south-westerly. The freezing level is about 1600 metres, lifting to 2300 metres before dawn tomorrow. A ridge of high pressure lies over the North Island today while a front affects the lower South Island. The ridge remains over the North Island on Wednesday while the front moves north and weakens, then another front approaches the South Island from the west late Wednesday.
Sliding Danger
Despite the recent new snow, the melt-freeze and rime crusts remain. Numerous hazards, such as exposed rocks and cliff bands, exist. Carrying an ice axe and crampons is recommended in the backcountry. It is essential to have strong alpine skills and competence when travelling over slick surfaces with high consequences.
Forecast Confidence
Moderate
- We have a good understanding of the snowpack structure and confidence in the weather forecast.
New Zealand Avalanche Advisory (NZ Mountain Safety Council)