Tongariro

Avalanche problems

• 

  Wind slab

  Wind slabs are formed when loose snow in near-surface layers (new snow or old snow) is transported and deposited by wind.

  Avoid wind-drifted deposits in steep terrain.

  Affected aspects

  WestNorthwestNorthNortheastEast
• 

  Wet snow

  The avalanche problem is related to a weakening of the snowpack due to the presence of liquid water. Water infiltrates the snowpack due to melt or rain.

  Good timing and trip planning are important. Consider avalanche runout zones.

  Affected aspects

  WestNorthwestNorthNortheastEast
• 

  Cornices

  A wave-like formation of soft or hard wind drifted snow, often overhanging.

  Avoid travel on and below large ridge-top cornices.

  Affected aspects

  NortheastEastSoutheastSouth

Stability

A minimal amount of loose snow is currently being transported to north- and east-facing aspects. Low-volume slabs are forming but are resistant to light loads. Light winds in the northwest areas with clear skies are prime conditions for surface breakdown. On average, the last storm cycle brought half a metre of new snow to the region at an elevation of 2000 metres. The older, deeper snowpack is consolidated and supportive. No step-down into the older snowpack was observed during testing over the past few days. Snow cover exists on Mt Ngauruhoe and Mt Tongariro. If doing the Tongariro crossing, you will be traveling over snow and ice. Alpine gear and precautions need to be considered. The south-west areas have enough snow cover in start zones above 1600 metres for avalanches to run freely (threshold). In the northern areas, the threshold is at a slightly higher elevation, but this is also changing fast. This recent snowfall has improved snow cover overall and lowered the threshold in the northern areas and east (about 1600 metres elevation). Check photo of the start zone and snow cover at Turoa (photo taken am 28072026), at 1750 metres, with a north-west aspect.

Snow quality

No human- or natural-triggered avalanche activity has been reported or observed over the past 24 hours.

Weather

Tomorrow, the 29th of July, will remain settled with fine, clear conditions. The winds will be moderate southerly, tending west / northwest and easing overnight into Wednesday. The freezing level is 2000 metres, lowering to 1200 metres for a time in the morning. A ridge of high pressure over the country moves slowly eastwards tomorrow as a front approaches from the Tasman Sea; meanwhile, a northwest flow builds over the South Island.