Bollettino valanghe

Ohau

New Zealand Avalanche Advisory
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Pericolo valanghe

High Alpine · above 1,800 m
1 · Debole
Alpine · 1,200 m–1,800 m
1 · Debole
Sub Alpine · below 1,200 m
1 · Debole
Non aggiornato — questo bollettino è scaduto 5 days ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Winds are picking up on Friday but with spring conditions across much of the forecast area the hazard should remain low. The corn should be good, and staying on sunny aspects will keep you away from sheltered south-east facing terrain where small wind slabs could be building.

Problemi valanghivi

  • Wind Slabs

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    Probabilità
    Possible
    Dimensione
    1

    With strong to gale northwesterly winds through Friday, wind slab avalanches are possible on sheltered east and south facing slopes near ridgeline.

    These will be small, but watch for blowing snow and exercise caution around steep, recently loaded terrain.

  • Loose Wet

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    Probabilità
    Unlikely
    Dimensione
    1

    There has been plenty of time for loose snow avalanches to flush out, but with another day of warm temperatures away from the Divide, you might be able to get a small loose wet avalanche moving on sunny slopes out of steep, rocky terrain.

    These avalanches will be small, but be wary of terrain traps like cliffs, gullies, exposed rocks or other hazards where a small slide can have big consequences.

Recent Avalanche Activity

Several small loose avalanches were observed on th 17th in The Barrier range. Mostly on eastern and northern aspects. Probably run at the tail end of the storm on the 16th.

Nothing observed since.

Current Snowpack Conditions

The snowpack across the forecast area is largely well settled.

Sunny slopes at all elevations are capped with a melt-freeze crust and a spring-like snowpack.

Shady slopes are holding a mix of around 10cm of dry, faceted powder in sheltered areas and windpressed powder in areas exposed to the southwesterly wind. This sits on a mix of old windscoured crusts and firm, wind-pressed snow above 2000m and a melt freeze crust at lower elevations.

Faceting has been observed in the lower pack, but after warm temperatures and lots of sun this should be limited to shady slopes above 2000m. There's no indication of instability in these layers.

Mountain Weather

Mainly fine with morning frost, severe in sheltered places. High cloud passing over from afternoon.

Wind at 1000 metres: Westerly 30 km/h, rising to northwesterly 50 km/h in the morning, then to gale 70 km/h in exposed places in the evening.

Wind at 2000 metres: Westerly 30 km/h, rising to northwesterly 50 km/h in the morning, then to northwesterly gale 70 km/h but severe gale 90 km/h in exposed places in the evening.

Freezing level: 2300 metres, but 1600 metres about the divide.

Sliding Danger

Beware of sliding falls! There will be slick surfaces on sunny slopes in the morning, and just under the new snow in the shade. Take an ice axe and crampons for any travel above the snow line.

Forecast Confidence

High

  • We have a good understanding of the snowpack structure and confidence in the weather forecast.

New Zealand Avalanche Advisory (NZ Mountain Safety Council)

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