Avalanche forecast

Arthur's Pass

New Zealand Avalanche Advisory
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Avalanche danger

High Alpine · above 1,800 m
3 · Considerable
Alpine · 1,200 m–1,800 m
3 · Considerable
Sub Alpine · below 1,200 m
2 · Moderate
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Out of date — this forecast expired 3 weeks ago. You’re viewing past conditions, not the current bulletin.

Highlights

Heavy snow on Friday turning to rain-on-snow later in the day will significantly increase the avalanche risk.

Consider if mountain travel on Friday is really necessary and, if so, stick to ridge lines and low angle terrain.

Trampers and other low elevation park users beware crossing gullies exposed from above. Safe travel is one at a time.

Avalanche problems

  • Wind Slabs

    • All elevations
    Likelihood
    Likely
    Size
    1.5

    Strong winds from the N through NW during Friday will transport significant snow ( possibly 60cm+) creating windslab on lee aspects.

    Transported snow may be blown lower than you expect, so beware snow density changes (stiffer, firmer snow) in unexpected places at mid elevations.

  • Loose Wet

    • All elevations
    Likelihood
    Likely
    Size
    1.5

    Afternoon/evening rain below 1800m will add considerable weight to the snowpack and raise the hazard of loose wet avalanches on all aspects.

Recent Avalanche Activity

No avalanche activity reported.

If you see anything, please report it in the public observations section of the NZAA website.

Current Snowpack Conditions

The upper snow pack has been settling out but field reports indicate possible weaknesses that the incoming storm may overload to trigger avalanches. There are wind stripped surfaces at higher elevations on NW through S aspects. Below this settling upper snow pack is a formerly wind pressed snowpack from earlier in the season with no significant layers of concern. There are limited observations of the new snow line around the forecast area, but threshold for avalanches is estimated at around 1500m in the west, tapering east. At lower elevations (below 2000m) ice crusts exist but bonding to the ice layers has been good.

Mountain Weather

Forecast for Friday 7th August

Cloud increasing in the morning with periods of rain, possibly heavy from afternoon, with snow to 1300 metres until evening.

Wind at 1000 metres

Northerly 40 km/h developing in the morning.

Wind at 2000 metres

Northwesterly 40 km/h, rising to gale 65 km/h for a time in the afternoon and evening.

Freezing level

1200 metres, lifting to 1800 metres in the evening.

Sliding Danger

Expect areas to be stripped back to hard surfaces from the gale winds at higher elevations. Crampons and an ice axe are a good idea, as many firmer areas now exist.

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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