Loose dry avalanches are possible on steep slopes. New snow accumulation has an even distribution, creating a loose dry avalanche concern. Tomorrow, a loose wet problem develops as the sun impacts this new snow. The next 24 hours, the weather improves, becoming settled with light winds and fine conditions.
Loose dry avalanche activity is possible. Turoa received 6 cm of new snow overnight with continued snowfall throughout today (20072026). Loose dry avalanches will be possible in steep terrain features on all aspects above 1900m over the next 24 hours. Triggering a weakness at the new old snow interface will be possible.
Loose wet avalanche activity will be possible on slopes being impacted by direct sun. Solar radiation will shock the new snow, resulting in a sensitive surface layer. 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 a developing instability.
No human or naturally triggered avalanches have been reported or observed over the past 24 hours.
Overnight snowfall accumulation was about 6cm. The new snow is of low-density and evenly distributed above 1600 metres elevation. Supporting this new snow lies an older consolidated snowpack. The older snowpack remains consolidated, with new snow weaknesses the primary concern currently. 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 enough snow cover in isolated start zones above 1600 metres, mostly on north and west aspects. South and east aspects remain sparse at lower elevations. In the northern areas, the threshold is at a higher elevation.
Today, snow showers are possible. Tomorrow, the 21st of July, will be fine. The winds will be light southeasterly, tending southerly. The freezing level is 800 metres overnight, lifting to 2000 metres in the morning. A complex trough over central New Zealand moves slowly across the North Island today, while a ridge builds over the country, south of the trough. Another front over the Tasman Sea moves onto the south of the South Island late in the day and across the lower South Island tomorrow.
Despite the new snow, the melt freeze and rime crusts remain. Exposure to wind will increase the risk of a sliding accident. Numerous hazards, such as exposed rocks and cliff bands, remain present. 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.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
