Skiers, snowboarders, hunters and trampers are being warned of that current snowpack conditions throughout many parts of the country present a heightened risk of avalanche.
Mountain Safety Council avalanche forecasters have identified a ‘persistent slab’ danger, which is present throughout many parts of the country, particularly Queenstown, Wanaka, Aoraki Mount Cook, Fiordland and Tongariro.
The weak persistent layer of snowpack could extend to other regions.
The nature of the problem lies deeper than the recent fresh snow, and it can become reactive under certain conditions.
International Federation of Mountain Guides Associations guide and coordinating forecaster Jamie Robertson says persistent slabs have the ability to be triggered by smaller avalanches and step down to the weaker layers, making the avalanches a lot bigger than expected.
“This is a complex problem and requires very careful management. We advise people to stick to low angle terrain or aspects that don’t have persistent layers.
“It’s imperative that people check all the details of the advisory, not just the headline danger level. There’s critical information within these forecasts that help to guide people to safe aspects and elevations.”
A significant snowfall is predicted for the weekend, therefore current avalanche dangers are likely to persist into next week.
Jamie says the recent avalanches are indicative of the kinds of large avalanches possible at the moment.
“The problem relates to more than just the new snow so management is more about avoiding the slopes that might have the persistent layers, you can’t trick the snowpack.”
Mountain Safety Council communications manager Nick Kingstone says the advisory has a public observation function on the site, and the council is encouraging the public to get involved in helping to keep the backcountry community safe.
“The NZAA has a ‘public observation’ feature on the homepage where people can enter their own observations. Our forecasters really value as much data as possible when they’re forecasting conditions in their region. It’s ideal if they add a photo if possible.
“If the forecasters have got dozens of recent observations of snow conditions or avalanches they’re able to refine their forecast. Ultimately, these forecasts are a vital decision-making tool and we’re relying on the backcountry users to add to the safety efforts for the wider community.”
“Excitingly, this year we’ve got great monthly prizes to incentivise people to add their observations. Head to the NZAA competitions page for more details”
For further information, visit the mountain safety council’s Facebook page dedicated to the snow and alpine community.