By Dan Satherley
A large, ominous-looking cloud formation could be the first new type of cloud to be formally recognised in six decades.
First photographed in 2006, the undulatus asperatus ("agitated wave") looks kind of like an upside-down mountain range, or waves caused by a storm at sea.
Backing the campaign to have the undulatus asperatus recognised is the UK-based Cloud Appreciation Society (CAS). Founder Gavin Pretor-Pinney says it could be the first "crowd-sourced" cloud discovery, but it won't be official until the UN's World Meteorological Organisation has accepted it.
It last updated its cloud bible, the International Cloud Atlas, in 1975, and the last new cloud formation was added way back in 1951.
"There are rumours that the UN organisation is considering the case for a new edition," Mr Pretor-Pinney told UK paper The Independent.
The CAS has more than 30,000 members, and with the release of a phone app next year, could very well uncover more rare types of clouds.
Since 2006, Undulatus asperatus clouds have been spotted in France, Scotland, the UK, the US and right here in New Zealand.
WeatherWatch.co.nz's Philip Duncan told 3 News the discovery of a new type of cloud is "sort of like discovering a new colour – there's a very limited amount of them".
"I think if we were to see them in New Zealand, they'd be quite likely around places like Otago and Canterbury," says Mr Duncan.
"We've had reports of similar-looking clouds, and certainly photos sent in to us over the years – some of them have looked quite similar."
He says there wouldn't yet be much known about how the undulatus asperatus cloud forms, but the landscape would probably play a big part.
"By the looks of the photos they seem to be quite big, brooding systems around mountains and around hills… places like Scotland, Norway, France and America, they're all areas that have got hills and mountains, and plenty of land around them."
Mr Duncan says the Coromandel could be another place to spot them.
"People forget the air operates exactly the same as the sea does – you end up with currents at different levels going in different directions, and so where you've got big fat clouds it usually really highlights those currents, and you can see them swirling around the mountains and the valleys and doing unusual things in the skies as the air actually bounces off the grounds and affects the clouds."
Mr Pretor-Pinney says it's unlikely the formation itself is new, just rare – but the proliferation of cellphone cameras and the internet have allowed sky-watchers to share and compare their discoveries.
"Observing the clouds is an important way of documenting the effect of global warming on the sky," he told The Independent.
Mr Pretor-Pinney says clouds may provide answers about temperature and climate change in years to come, but Mr Duncan isn't so sure.
"Anything more that you can learn about the atmosphere plays a key role in understanding what is happening to our planet… but learning more about this one cloud I don't think is going to have a major impact.
"It would have more of an impact on human beings if these clouds were very widespread and they lead to something – we could find out that they are a precursor to a thunderstorm or a snow event – that's when that information becomes useful."
The video above was shot by WeatherWatch.co.nz reader Geoff Blackmore in the Hawke's Bay last year. He says he didn't know at the time what it was, but in a strange coincedence, posted it on the WeatherWatch.co.nz Facebook page the same day 3 News contacted Mr Duncan for comment on the formation.
Though undulatus asperatus clouds were first photographed only five years ago, chances are we'll be seeing a lot more of them – if only on the internet.
"When I look at the photos that come into WeatherWatch, the majority of photos we get are cloud ones," says Mr Duncan.
"People love clouds, and in this country we have no shortage of them."