Avalanche forecast

Two Thumbs

New Zealand Avalanche Advisory
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Avalanche danger

High Alpine · above 1,800 m
1 · Low
Alpine · 1,200 m–1,800 m
1 · Low
Sub Alpine · below 1,200 m
1 · Low
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Highlights

The snowpack in the Two Thumb Range is mostly stable.

Some isolated pockets of reactive windslab could still be lurking at higher elevation

It's a good day to get out in the hills and enjoy the short lull in the recent relentless wind.

Avalanche problems

  • Wind Slabs

    • All elevations
    Likelihood
    Unlikely
    Size
    1

    Previous windslabs are bonding and gaining strength. Isolated slopes may be able to be trigged by a single person's weight. Even a small avalanche may be consequential with rocks or cliffs in the runout.

  • Loose Wet

    • All elevations
    Likelihood
    Unlikely
    Size
    1

    A solid freeze is expected overnight. Combined with a dry SW wind, this should keep the loose wet danger away.

    However, a warm day is forecast, and it's possible that enough heat will get through to cause a problem.

    Take care to observe the state of the snow and be prepared to avoid steep slopes and runouts if the snowpack loses strength.

Recent Avalanche Activity

A size 1 (too small to bury a person) windslab avalanche occurred naturally on south east facing terrain at 1500m some time last week.

There have been no other reported avalanches in the area.

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

Current Snowpack Conditions

South westerly winds have redistributed what little transportable snow that was left after severe gale NW winds that have stripped snow earlier this week. This wind has left old crusts and rock exposed on North and West facing slopes.

Below about 1800-2000m the snowpack has become wet and gone through overnight freezes.

Snow depths in the south are about 70cm, tapering to about about 50cm mid range and 40cm in the north.

The snowpack north of Stag Saddle is not well understood, with no direct observations.

Mountain Weather

Morning cloud clearing to fine. Areas of morning frost.

Wind at 1000 metres

Light, westerly 30 km/h developing at night.

Wind at 2000 metres

Light, southwesterly 30 km/h developing in the evening.

Freezing level

1400 metres rising to 1700 metres in the afternoon.

Sliding Danger

The wind has stripped the soft snow back to exposed crusts.

Below 2000m, the snowpack has gone through melt freeze cycles, so any overnight freeze will form a slick crust.

Expect high sliding danger with lots of rocks in the runouts.

Iceaxe and crampons are recommended.

Forecast Confidence

Moderate

  • We are confident due to a stable weather pattern.
  • We have a good understanding of the snowpack structure and confidence in the weather forecast.
  • We are uncertain about how the timing or intensity of solar radiation will affect the snowpack.

New Zealand Avalanche Advisory (NZ Mountain Safety Council)

Regions covered