Avalanche forecast

Tongariro

New Zealand Avalanche Advisory
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Avalanche danger

High Alpine · above 2,300 m
3 · Considerable
Alpine · 1,800 m–2,300 m
2 · Moderate
Sub Alpine · below 1,800 m
1 · Low
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Highlights

Wind slabs exist and will require time to consolidate and strengthen. Over the next 24 hours, multiple avalanche hazards will be present in the Tongariro alpine backcountry. The recent storm system has delivered a decent amount of new snow, with large wind slabs forming. The weather is settled over the next 24 hours as a ridge of high-pressure effects the region. Recommend a conservative mindset if you do venture into the alpine backcountry.

Avalanche problems

  • Wind Slabs

    • All elevations
    Likelihood
    Possible
    Size
    2.5

    Wind slabs exist on multiple aspects. Strong to gale winds have redistributed the new snow over the past few days. The loading aspects were mostly south- and east-facing, but wind direction shifted during the storm, expanding the area of concern. Wind-driven snow deposits have also formed near sheltered terrain features, such as ridgelines and rocky outcrops. Weaknesses are present, with triggering likely at start zones that are steep and lacking support. Recommend maintaining a conservative mindset and a cautious approach to any loaded slope.

  • Loose Wet

    • All elevations
    Likelihood
    Possible
    Size
    1.5

    Loose wet avalanche activity will become possible on solar aspects over the next 24 hours. At some locations, the new snow is evenly distributed down to 1600 metres in elevation. In the next few days, solar radiation will be intense with clear skies forecasted throughout Monday, the 27th of July. Loose wet activity will be specific to steep sun-affected slopes. The warmest period of the day will be the height for activity. Watch for point release activity and roller ball near and under cliffs and rock bands.

  • Cornices

    • All elevations
    Likelihood
    Possible
    Size
    1.5

    Cornice formation has occurred. Cornice formations will be isolated to south- and east-facing ridgelines. Cornices will be touchy to light loads, as most lack any decent support. Failure will remain a possibility. Triggering a localised wind slab will be possible. Recommend avoidance and maintaining a decent distance even after the storm event.

Recent Avalanche Activity

Multiple avalanches were triggered by ski patrols during slope assessment this morning, up to size 2. Debris from size 1 natural avalanches has been observed by Whakapapa and Turoa ski patrols today (25072026).

Current Snowpack Conditions

On average, half a metre of new snow has fallen at an elevation of 2000 metres. This new snow has been redistributed, forming wind slab deposits over 100 cm in depth on multiple aspects (Turoa). New snow instabilities have been tested by ski patrols mostly around Turoa. Multiple avalanches have been triggered during slope assessment this morning (26072026). One avalanche was triggered by a significant load at 2500 metres elevation in Turoa backcountry (result classed as size 2). The older deeper snowpack seems to be consolidated and supportive with no step down into the older snowpack. Snow cover exists on Mt Ngauruhoe and Mt Tongariro. The south-west areas have enough snow cover in start zones above 1600 metres for avalanches to run freely (threshold). In the northern areas, the threshold is at a slightly higher elevation, but this is also changing fast. This recent snowfall has improved snow cover overall and lowered the threshold in the northern areas and east (about 1600 metres elevation). Check photo taken today from Ohakune (26072026).

Mountain Weather

Monday the 27th of July will be fine and clear. The winds are mostly from a southerly direction and light. The freezing level is 900 metres, lifting to 1200 metres in the morning. A low is expected to move quickly east across the northern North Island today, while another low lingers near the Chatham Islands and deepens. A ridge of high pressure then spreads across most of New Zealand by the end of the day today and extends towards the Chatham Islands tomorrow.

Sliding Danger

Slick rime crusts exist, presenting a sliding hazard. The strong to gale winds have stripped the new snow, exposing these crusts on ridgelines and windward terrain features. Numerous hazards, such as exposed rocks and cliff bands, remain. 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.
  • We are uncertain due to the variability of wind effect on the snowpack.

New Zealand Avalanche Advisory (NZ Mountain Safety Council)

Regions covered