Avalanche forecast

Arthur's Pass

New Zealand Avalanche Advisory
View on map

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
1 · Low
Open full map
Out of date — this forecast expired 3 weeks ago. You’re viewing past conditions, not the current bulletin.

Highlights

As the winds increase and change direction over Monday night into Tuesday the wind slab hazard will also increase. Look for transporting snow to indicate increasing hazard.

Route selection should allow for changing hazard during the day.

Avalanche problems

  • Wind Slabs

    • All elevations
    Likelihood
    Possible
    Size
    2

    As the winds increase, the wind slab hazard will also increase. Look for transporting snow to indicate increasing hazard.

  • Loose Wet

    • All elevations
    Likelihood
    Possible
    Size
    1.5

    If the sun comes out tomorrow, the loose wet hazard will increase during the day.

Recent Avalanche Activity

A loose wet avalanche cycle was observed beginning on solar/sunny aspects further south in the range on 2 August.

Size 1 wind slab triggered 1 Aug. See public observation.

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

Current Snowpack Conditions

The new snow from 31 July (down to 1500m in the west) has now had three days to consolidate and with warm temps on the 2nd and 3rd August most storm instabilities are likely to have settled out. However, strong winds over the last 24hrs from the west, and moving tonight through southwest and southerly quarters, will be shifting the storm snow around. Expect wind stripped surfaces at higher elevations on W-NW aspects, with some deep pockets in the lees. On Monday night loose snow will be transported by SW and S winds to produce a complex layering in the near surface snowpack. Below this is a formerly wind pressed snowpack with no significant layers of concern. Limited observations of the new snow line around the forecast area, but estimated around 1500m in the west. At lower elevations (below 2000m) ice crusts exist but bonding to the ice layers has been good.

Mountain Weather

Forecast for Tuesday 4th August

Mostly cloudy. A few snow showers, clearing in the afternoon.

Wind at 1000 metres

Southerly 30 km/h, rising to 50 km/h in the afternoon.

Wind at 2000 metres

Southwesterly 40 km/h. Rising to gale 80 km/h before dawn, gusting severe gale 100 km/h in the evening.

Freezing level

700 metres lowering to 200 metres by 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 uncertain due to a limited number of field observations.
  • We are uncertain about forecast precipitation amounts.
  • We are uncertain due to the variability of wind effect on the snowpack.

New Zealand Avalanche Advisory (NZ Mountain Safety Council)

Regions covered