Wind slab formation is a possibility. Low-volume wind slabs may form on aspects facing mostly south above 2300 metres elevation. A loose wet avalanche problem may develop as rain showers continue to impact the snow surface at lower elevations. The changeable and unsettled weather continues over the next 24 hours. Winds are strong tomorrow, then becoming gale in the morning.
Wind slabs may form at higher elevations (above 2300 metres). These wind slabs will be low volume and primarily located on south-facing slopes. Eastern slopes may also have wind-transported deposits. Although warmer temperatures can promote bonding, triggering avalanches on steeper slopes will still be a possibility. Terrain features such as gullies and rocky outcrops can serve as catchment areas where loading is more likely to occur.
Loose wet avalanche activity is possible as light rain showers continue over the next 24 hours. The surface structure will be reduced by these passing showers. Rising freezing levels will result in light rain in the higher elevations at times. Forecasted precipitation is not significant, and deep saturation is unlikely to occur. Triggering is possible at isolated steeper start zones that lack support.
No human or naturally triggered avalanches have been reported or observed over the past 24 hours.
Over the past 24 hours, light rain has impacted the snowpack below 2300 metres. Elevated temperatures and high water content have contributed to the bonding process. The snowpack is displaying signs of traveling in the right direction, becoming consolidated. A crust has also formed at the lower elevations. A few days ago, snowfall accumulation was noted on Mt Ngauruhoe and Mt Tongariro. The southwest areas of the region have isolated start zones on the north and west aspects above 1600 metres and have enough snow for avalanches to run. Check the photo of Hamilton's face at Turoa. The northern areas have a higher threshold elevation.
Thursday, the 16th of July, will have a few showers. The winds are westerly, rising to a gale in the morning and afternoon. The freezing level is about 2400 metres above sea level. Disturbed north westerlies cover the country today, Wednesday, while a shallow low and its associated front over the Tasman Sea move east across the South Island. Another front approaches the far south of the South Island from the southwest tonight. Both features move northeast over the country and weaken tomorrow. Then a south-westerly flow develops.
Recent formation of rain and rime crusts is increasing the risk of sliding hazard. Windward and exposed areas have been stripped by gale winds during the past storm cycle a few days ago. This has exposed an icy rime crust on slopes above 1400 metres. Plenty of hazards, such as exposed rocks and cliff bands, remain. It's essential to carry the appropriate gear, crampons, and an ice axe. A targeted skill set will reduce the chance of an accident.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
