Avalanche forecast

Two Thumbs

New Zealand Avalanche Advisory
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Avalanche danger

High Alpine · above 1,800 m
4 · High
Alpine · 1,200 m–1,800 m
3 · Considerable
Sub Alpine · below 1,200 m
2 · Moderate
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Highlights

Higher elevation terrain has received a lot of snow that will need time to settle.

Lower down, rain has weakened the snowpack.

Travel in avalanche terrain is not recommended.

Avalanche problems

  • Wind Slabs

    • All elevations
    Likelihood
    Likely
    Size
    2

    Gale northwesterlies will build fresh windslabs onto slopes that face south, southeast and east.

    This problem will be mainly found above about 2000m where there is more wind transportable snow.

  • Loose Wet

    • All elevations
    Likelihood
    Possible
    Size
    2

    Below about 2100m the snowpack has received a lot of rain. With this level of snowpack saturation, large natural loose wet and wet slab avalanches are possible. Be mindful of what is above you especially if the rain continues.

    The snowpack will need time for water to drain.

  • Storm Slabs

    • All elevations
    Likelihood
    Likely
    Size
    2

    More than 50cm of snow has fallen above about 2200m. Some terrain will be loaded with more than this as strong winds, first from the northeast and then the northwest will have transported snow to lee slopes.

    This snow needs time to gain strength and bond.

    Travel in avalanche terrain is not recommended

Recent Avalanche Activity

No recent avalanches have been reported in the area. However, observations have been limited due to the ongoing storm.

If you see any activity on the Two Thumb Range, please make a public observation. It helps us to produce accurate forecasts.

Current Snowpack Conditions

The tops of the highest peaks in the area have received a lot of new snow -possibly up to 100cm.

Rain has saturated the snowpack below about 2100m. A brief cold snap on Wednesday night delivered about 5-10cm of fresh snow to low levels before turning back to rain.

Prior to the storm the old snow pack was well settled with wind blown pockets sitting over surface crusts in most places.

Snow depth varies from 40-75cm, with deeper accumulations of 100-120cm in sheltered areas.

Mountain Weather

Scattered rain, falling as snow above 1300 metres, clearing throughout the afternoon as fine breaks develop.

Wind at 1000 metres

Gale northwesterly 65 km/h.

Wind at 2000 metres

Severe gale northwesterly 120 km/h, easing to westerly gale 70 km/h early evening.

Freezing level

2100 metres, lowering to 1800 metres in the evening.

Sliding Danger

Rain followed by heavy snow should keep the sliding danger away for the next few days.

Be aware that the saturated snowpack will be very slick as soon as it freezes. Even a brief spell of night time clear skies could rapidly increase the sliding danger.

Forecast Confidence

Low

  • We are uncertain due to a limited number of field observations.
  • We are uncertain about forecast precipitation amounts.
  • We are uncertain due to variable freezing levels.

New Zealand Avalanche Advisory (NZ Mountain Safety Council)

Regions covered