Alabama skies covered by stunning wave clouds
UPDATE: March 4, 2016, 10:02 a.m. EST A spokesperson for the World Meteorological Organization has clarified, in an email to Mashable, that the time-consuming part of updating the new International Cloud Atlas is the process of collecting all the new images of clouds from around the world.
The skies above Alabama on Thursday were transformed into a rare display of a cloud known as undulatus, as well as an even more rare and highly prized cloud formation among atmospheric aficionados: undulatus asperatus.
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Undulatus asperatus, or turbulent wave clouds, have been the subject of a quixotic advocacy campaign by the UK-based Cloud Appreciation Society, which is a lobbying group for cloud fanatics worldwide.
Social media posts show that the sky was full of undulatus, or "wavy," clouds above Alabama as a mixture of sleet, snow and rain moved into the region on Thursday morning. Both types of clouds reveal turbulent wave motion of varying amplitudes.
The World Meteorological Organization (WMO) defines undulatus asperatus clouds as:
"A formation made up of well-defined, wavelike structures in the underside of the cloud, more chaotic and with less horizontal organization than undulatus. It is characterised by localized waves in the cloud base, either smooth or dappled with smaller features, sometimes descending into sharp points, as if viewing a roughened sea surface from below. Varying levels of illumination and thickness of cloud can lead to dramatic visual effects."
The WMO notes that undulatus already exists as a cloud variety, and a WMO team has proposed that "asperitas," derived from the Latin word for roughness, be added as a supplementary feature.
That decision is still pending work by the WMO executive council, which means that cloud policy red tape is slowing things down.
Here are a few other examples of undulatus clouds from recent years, including this view from the Mount Washington Observatory in New Hampshire in January:
This is a timelapse video from Nebraska in 2014, as a thunderstorm accompanied by undulatus asperatus clouds moved through.
If you see these clouds in the future, let us know via Twitter or Instagram. We think they're pretty rad.
Andrew Freedman is Mashable's Senior Editor for Science and Special Projects. Prior to working at Mashable, Freedman was a Senior Science writer for Climate Central. He has also worked as a reporter for Congressional Quarterly and Greenwire/E&E Daily. His writing has also appeared in the Washington Post, online at The Weather Channel, and washingtonpost.com, where he wrote a weekly climate science column for the "Capital Weather Gang" blog. He has provided commentary on climate science and policy for Sky News, CBC Radio, NPR, Al Jazeera, Sirius XM Radio, PBS NewsHour, and other national and international outlets. He holds a Masters in Climate and Society from Columbia University, and a Masters in Law and Diplomacy from The Fletcher School at Tufts University.
