Undulatus asperatus (or alternately, asperatus) is a rare, newly recognized cloud formation, that was proposed in 2009 as the first cloud formation added since cirrus intortus in 1951 to the International Cloud Atlas of the World Meteorological Organization. The name translates approximately as roughened or agitated waves.
Margaret LeMone, a cloud expert with the National Center for Atmospheric Research has taken photos of asperatus clouds for 30 years, and considers it a likely new cloud type. On June 20, 2006 Jane Wiggins took a picture of asperatus clouds from the window of a downtown office building in Cedar Rapids, Iowa. In 2009 Gavin Pretor-Pinney, founder of the Cloud Appreciation Society, came across the image and began working through the Royal Meteorological Society to promote the cloud type. Wiggins' photograph was posted on the National Geographic website on June 4, 2009.
The clouds are most closely related to undulatus clouds. Although they appear dark and storm-like, they tend to dissipate without a storm forming. The ominous-looking clouds have been particularly common in the Plains states of the United States, often during the morning or midday hours following convective thunderstorm activity. As of June, 2009 the Royal Meteorological Society is gathering evidence of the type of weather patterns in which undulus asperatus clouds appear, so as to study how they form and decide whether they are distinct from other undulatus clouds.
Whipped into fantastical shapes, these clouds hang over the darkening landscape like the harbingers of a mighty storm.
But despite their stunning and frequent appearances, the formations have yet to be officially recognised with a name.
They have been seen all over Britain in different forms - from Snowdonia to the Scottish Highlands - and in other parts of the world such as New Zealand, but usually break up without producing a storm.
And some experts believe the stormy weather phenomenon deserves its very own classification.
Experts at the Royal Meteorological Society are now attempting to make it official by naming it 'Asperatus' after the Latin word for 'rough'.
If they are successful, it would be the first variety of cloud formation to be given a new label in over half a century
'It is a bit like looking at the surface of a choppy sea from below,' said Gavin Pretor-Pinney, founder of the Cloud Appreciation Society, who identified the cloud from photographs sent in by members.
We try to identify and classify all of the images of clouds we get in, but there were some that just didn't seem to fit in any of the other categories, so I began to think it might be a unique type of cloud.'
He added: 'The underside of the clouds are quite rough and choppy. It looks very stormy, but some of the reports we have been getting suggest that they tend to break up without actually turning into a storm.'
The Royal Meteorological Society is now gathering detailed information for the days and locations where the asperatus clouds have been seen in an attempt to understand exactly what is causing them.
Officials will then apply to the UN's World Meteorological Organisation in Geneva to have the new cloud type considered for addition into the International Cloud Atlas, the system used by meteorologists across the globe.
Professor Paul Hardaker, Chief Executive of the RMS, said: 'There would probably need to be quite a lot of heat around to produce the energy needed to generate such dramatic cloud formations.
'They are quite dark structures so there must be a lot of water vapour condensing in the cloud.'
Margaret LeMone, a cloud expert with the National Center for Atmospheric Research has taken photos of asperatus clouds for 30 years, and considers it a likely new cloud type. On June 20, 2006 Jane Wiggins took a picture of asperatus clouds from the window of a downtown office building in Cedar Rapids, Iowa. In 2009 Gavin Pretor-Pinney, founder of the Cloud Appreciation Society, came across the image and began working through the Royal Meteorological Society to promote the cloud type. Wiggins' photograph was posted on the National Geographic website on June 4, 2009.
The clouds are most closely related to undulatus clouds. Although they appear dark and storm-like, they tend to dissipate without a storm forming. The ominous-looking clouds have been particularly common in the Plains states of the United States, often during the morning or midday hours following convective thunderstorm activity. As of June, 2009 the Royal Meteorological Society is gathering evidence of the type of weather patterns in which undulus asperatus clouds appear, so as to study how they form and decide whether they are distinct from other undulatus clouds.
Whipped into fantastical shapes, these clouds hang over the darkening landscape like the harbingers of a mighty storm.
But despite their stunning and frequent appearances, the formations have yet to be officially recognised with a name.
They have been seen all over Britain in different forms - from Snowdonia to the Scottish Highlands - and in other parts of the world such as New Zealand, but usually break up without producing a storm.
Stunning but undefined: The clouds loom over the skies of New Zealand - but unfortunately words can't describe this dramatic vision from the heavens
And some experts believe the stormy weather phenomenon deserves its very own classification.
Experts at the Royal Meteorological Society are now attempting to make it official by naming it 'Asperatus' after the Latin word for 'rough'.
If they are successful, it would be the first variety of cloud formation to be given a new label in over half a century
'It is a bit like looking at the surface of a choppy sea from below,' said Gavin Pretor-Pinney, founder of the Cloud Appreciation Society, who identified the cloud from photographs sent in by members.
Dramatic: The ribbons across the sky look like a 'choppy sea viewed from below'
We try to identify and classify all of the images of clouds we get in, but there were some that just didn't seem to fit in any of the other categories, so I began to think it might be a unique type of cloud.'
He added: 'The underside of the clouds are quite rough and choppy. It looks very stormy, but some of the reports we have been getting suggest that they tend to break up without actually turning into a storm.'
The Royal Meteorological Society is now gathering detailed information for the days and locations where the asperatus clouds have been seen in an attempt to understand exactly what is causing them.
Officials will then apply to the UN's World Meteorological Organisation in Geneva to have the new cloud type considered for addition into the International Cloud Atlas, the system used by meteorologists across the globe.
Professor Paul Hardaker, Chief Executive of the RMS, said: 'There would probably need to be quite a lot of heat around to produce the energy needed to generate such dramatic cloud formations.
'They are quite dark structures so there must be a lot of water vapour condensing in the cloud.'
Skies over Scotland: This scene from Perthshire could help confirm the new 'Asperatus' classification