Bollettino valanghe

Ohau

New Zealand Avalanche Advisory
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Pericolo valanghe

High Alpine · above 1,800 m
3 · Marcato
Alpine · 1,200 m–1,800 m
2 · Moderato
Sub Alpine · below 1,200 m
1 · Debole
Non aggiornato — questo bollettino è scaduto 4 weeks ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Fresh snow and strong NW winds are forecast for Thursday and Friday.

Expect increasing avalanche danger as fresh wind slabs develop and rain-on-snow weakens the existing snowpack.

Choose conservative terrain, avoid steep wind-loaded slopes and areas affected by rain, and reassess conditions carefully as the storm progresses.

Problemi valanghivi

  • Wind Slabs

    • Tutte le quote
    Probabilità
    Likely
    Dimensione
    1.5

    Wind slab danger is increasing on NE through SW aspects above 1500m as strong NW winds transport fresh snow from Thursday into Friday. The winds will shift to Southerly from Friday evening.

    Around 30 cm of new snow is expected, and strong winds will likely redistribute it into lee terrain, forming fresh wind slabs.

    Be cautious around ridgelines, gullies, and other wind-loaded features where these slabs are most likely to develop.

Recent Avalanche Activity

27 July - Two loose wet avalanches were observed on north-facing slopes.26 July - Several size 1 wind slabs were observed or triggered by ohau ski patrol team below ridge crest on E to SE aspects.

Current Snowpack Conditions

Approximately 15–20 cm of new snow fell between 23–24 July, accompanied by strong northwesterly winds that later shifted southwest. Since the storm, consecutive cold, clear nights have promoted near-surface faceting, preserving dry, and low-density snow.

Strong northwesterly and southwesterly winds formed wind slabs on East to South aspects during the storm cycle. These slabs have continued to stabilise and have shown little to no reactivity in recent stability assessments.

Mountain Weather

Periods of rain, heavy at times about the Divide until evening. Snow to 800 metres, lowering to 400 metres in the afternoon.

wind at top

Northwesterly 50 km/h changing southerly 40 km/h early evening.

freezing level

1100 lowering to 700 metres evening.

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 and may be cunningly hidden under new snow.

Forecast Confidence

Moderate

  • We are confident the likelihood of avalanches will increase with the forecast weather.
  • We are uncertain about forecast precipitation amounts.

New Zealand Avalanche Advisory (NZ Mountain Safety Council)

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