Media Release: ‘Dust On Crust’ Concerns Avalanche Forecasters

Avalanche forecasters for the New Zealand Avalanche Advisory (NZAA) are increasingly concerned about upcoming weather conditions. With a long period of warmer weather and a big dump on the way, conditions are likely to be very tricky in the backcountry said Mountain Safety Council (MSC) spokesperson Mike Daisley.

“We’ve had long fine spells and a shallow snowpack in early winter. Chatting to our forecasters around the country they are very concerned about it.”

The forecasters note that there is cause for concern that the conditions have set up trouble later in the season thanks to the strong temperature gradients that develop within the snowpack promoting faceting or re-crystallisation of the snow grains.

Daisley said that MSC, who run New Zealand’s avalanche forecast site Avalanche.net (NZAA) advise that backcountry travel is not advised.

“We’ve got a persist persistent weak layer throughout the Southern Alps that will become reactive with the additional snow loading that is forecast over the next few days.”

Daisley is keen to point out that there are tools available to help with any backcountry trip.

“We run Avalanche.net so people can get a better idea what the risks are before they head into the backcountry.”

“The avalanche forecast is one of several things you need to check or take before you go backcountry”

“If you are untrained in rescue techniques, lack the appropriate gear or have no idea what the conditions are, please think carefully about why you’re going backcountry.”

Weather forecasts suggest circumstances in the Southern Alps are about to change with the arrival of the next big storm. Cracking and settlements have been experienced on the main divide and point to signs of instability that have arisen as a result of heavy snow loading over a rain crust that had a thin layer of very weak snow on top of it. 
 
The surface conditions often known as ‘dust on crust’ are reported to be widespread throughout the Alps east of the divide. Dangerous avalanche conditions may develop once the ‘Crust Facet’ layer is buried. 
 
Daisley said that the MSC forecast team advise all backcountry should be carefully planned. 
 
“If you’re new to backcountry snow adventures, then please take extra precautions if you’re going out so you’ll make it home to your family”

The New Zealand Avalanche Advisory (NZAA) can be found at www.avalanche.net.nz 
 
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NOTES FOR EDITOR: 
Spokesperson: Mike Daisley 
 
Mike Daisley 
Chief Executive 
Cell: 027 443 7557 
Email: mike.daisley@mountainsafety.org.nz 
 
Nick Kingstone 
Communications Manager 
Cell: 021 190 2930 
Email: nick.kingstone@mountainsafety.org.nz 
 
About the New Zealand Mountain Safety Council: 
 
The New Zealand Mountain Safety Council (MSC) is a national organisation with a mandate from our member organisations to encourage safe participation in land-based outdoor activities. We facilitate the setting of standards, create and distribute resources, lead public awareness campaigns and foster positive support in the community so that more people can discover and enjoy New Zealand’s outdoors safely