Tongariro — Avalanche Forecast

There have been no reports or observations of avalanche activity in the past 24 hours.  Monday the 16th of November will have the odd shower clearing in the morning as fine breaks increase, but rain developing in the evening. The winds are moderate northerlies tending northwest and increasing throughout the day. Winds will become gale at the higher elevations. The freezing level is above 3000 metres elevation. A slow-moving front moves onto the South Island today, with a warm, humid northwest flow ahead of it. Tomorrow, the front gradually moves northeast to central New Zealand, while a ridge builds over the South Island.  Slick crust may form overnight. Currently, a melt-freeze cycle is affecting the snowpack. Advisable to assess surface conditions before starting an ascent and adjust your timeline if required.  A multitude of weather effects can rapidly change surface snow hardness. Wet, saturated snowpacks can refreeze overnight, resulting in a slick and dangerous surface crust. Under favourable conditions, rime can form during precipitation events, creating an icy, treacherous surface. On clear, fine days at sunset, refreezing can occur quickly and catch people out. A loss of footing can lead to an uncontrolled slide, and numerous impact hazards exist, including exposed rocks and cliff bands. It is recommended to carry an ice axe and crampons when venturing into the backcountry. Strong alpine skills are essential for navigating slick surfaces, as a sliding accident can have severe consequences.  

Even though overnight clear skies helped to maintain a low relative humidity, the temperatures were elevated, with an overnight minimum of plus 5c at 2000 metres elevation. A superficial refreeze overnight was possible at the higher elevations. Over the past 24 hours, no precipitation has affected the snowpack. The superficial overnight refreeze at the higher elevations would have improved stability above 2300 metres. Below 2300 metres in elevation, waterfalls are open and are free-flowing. At lower elevations, the snowpack continues to erode, leading to rising snowlines, which is typical for spring. Spring hazards exist. Waterfall holes and flowing water beneath unstable snow in gullies. Waterfall holes are especially dangerous during spring and are predominantly found in lower-elevation gullies. Ice falls are also possible. Ice falls are unpredictable and more likely during the warmest part of the day or rapid warming events. Be alert to your surroundings and react to recent signs of activity such as roller ball. Roller ball activity is a classic indicator that the surface has lost structural integrity.  Glide cracks are present, creating hazards below breakovers and often difficult to see during rapid descents. Snow cover is retreating, but you can still find good lines in the southwest. Isolated slopes in the southwest with an east and south aspect still have enough snow for an avalanche to run. The threshold is around 2000 metres in elevation.