Boletín de aludes

Ohau

New Zealand Avalanche Advisory
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Peligro de aludes

High Alpine · above 1,800 m
4 · Fuerte
Alpine · 1,200 m–1,800 m
3 · Notable
Sub Alpine · below 1,200 m
2 · Moderado
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Lo esencial

Snow is expected to low elevations on Thursday. Gale winds developing through the day will build large and dangerous wind slabs. Avoid travel in avalanche terrain.

Problemas de aludes

  • Wind Slabs

    • Todas las altitudes
    Probabilidad
    Very Likely
    Tamaño
    3

    There is forecast to be lots of new snow available for transport with moderate easterly winds in the morning and gale and severe gale northeasterlies and northerlies later in the day. Expect wind slab in sheltered areas near ridgeline on southeast through to northwest facing slopes at all elevations.

    Wind slab can build with moderate winds, so expect slabs to form before the northerly change in the afternoon.

    Old windslabs from northwesterly winds may still be lurking above 2200m on NE through to SW facing slopes. These will likely be covered by new snow and be hard to detect.

    Avoid travel in avalanche terrain.

  • Storm Slabs

    • Todas las altitudes
    Probabilidad
    Very Likely
    Tamaño
    2

    Storm slab avalanches are very likely on all aspects and elevations in the new snow in the morning, especially if snow totals are at the higher end of the forecast range (above around 50cm).

    As winds increase through the day, expect this hazard to persist in sheltered areas while wind slab builds in deposition zones near ridgeline.

  • Loose Dry

    • Todas las altitudes
    Probabilidad
    Likely
    Tamaño
    1

    Loose dry avalanches are possible in the new snow out of steep terrain. As freezing levels rise in the afternoon, these could look more like loose wet avalanches.

    There is the potential for loose snow avalanches to trigger larger and more destructive storm or wind slab avalanches.

Recent Avalanche Activity

Observations remain limited by bad weather. Ohau Ski Patrol reported:

26/8/26: Several size 1 loose wet avalanches from ski cutting at around 1900m on NE and SE aspects

25/8/26: One natural size 1 wind slab on a northeast aspect near ridgeline on the 25th of August

23/8/26: A natural wind slab avalanche cycle in sheltered terrain near ridgeline, with several size 1 avalanches and one size 2 avalanche on northeast through to south facing slopes.

Current Snowpack Conditions

We still have limited field observations due to the ongoing storm. It looks like roughly 55mm of precipitation has fallen in the south of the forecast area, with much of this falling as rain below roughly 2200m. Towards the Divide, heavy falls today have brought the estimated total precipitation from the storm to over 100mm. That means that above roughly 2200m there's 50cm to 1m of new snow (more towards the Divide), and below 2200m the snowpack is rainsoaked and saturated. Freezing level has fallen from Wednesday afternoon and should stay fairly low through Thursday, with forecasts ranging from 40cm to as much as 70cm of new snow down to low elevations.

At upper elevations, new snow from early in the storm was redistributed by gale and severe gale westerly winds, leaving a mix of scoured surfaces in exposed areas and deeper drifts of windblown snow in sheltered areas.

Mountain Weather

Rain, heavy at times about the Divide, easing about the foothills in the evening. Snow lowering to 400 metres before dawn, affecting high-level roads, then lifting to 1800 metres from the north in the afternoon and early evening.

Wind at 1000 metres: Easterly 40 km/h, rising to gale northeasterly 70 km/h about the Mackenzie Basin in the morning.

Wind at 2000 metres: Easterly 45 km/h, rising to gale northeasterly 65 km/h in the morning, and to northerly severe gale 120 km/h in the afternoon.

Freezing level: 1200 metres, lowering to 800 metres before dawn. Lifting to 2100 metres in the evening.

Sliding Danger

New snow should bury any crusts on Thursday.

Forecast Confidence

Low

  • We are confident the likelihood of avalanches will increase with the forecast weather.
  • We are uncertain due to a limited number of field observations.
  • We are uncertain about forecast precipitation amounts.

New Zealand Avalanche Advisory (NZ Mountain Safety Council)

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