Undulatus asperatus
© James Spann/Facebook
It was all eyes to the sky in Alabama after a rare cloud formation known as "undulatus asperatus" formed, creating amazing wavelike formations.

The clouds caught the attention of early risers, who posted images on social media sites, with many simply describing them as "stunning".
Undulatus asperatus

One YouTube user even managed to capture the clouds as they moved overhead, creating this mesmerizing time-lapse.

There is an ongoing argument among cloud fanatics as to whether these so called "undulatus asperatus" clouds should be recognized as a separate formation or just a subset of "undulatus" clouds, which look very similar.

The World Meteorological Organization is currently collecting evidence to decide on the matter as part of its revision of the International Cloud Atlas.

The Cloud Appreciation Society, based in the UK, is leading the charge to have the "asperatus" (Latin adjective meaning 'rough') officially recognized as a unique formation.

They have identified the "well-defined, wavelike structures in the underside of the cloud" as being "more chaotic and with less horizontal organization than undulates."