A Polish Army tank takes part in the NATO Noble Jump exercise on a training range near Swietoszow Zagan, Poland, Thursday, June 18, 2015. (AP Photo/Alik Keplicz)

Undulatus asperatus (or alternately, asperatus) is a cloud formation, proposed in 2009 as a separate cloud classification by the founder of the Cloud Appreciation Society. If successful it will be 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”.

A female sniper of the Syrian Democratic Forces (SDF) monitors the area during a celebration at the iconic Al- Naim square in Raqa on October 19, 2017, after retaking the city from Islamic State (IS) group fighters. The SDF fighters flushed jihadist holdouts from Raqa' s main hospital and municipal stadium, wrapping up a more than four- month offensive against what used to be the inner sanctum of IS' s self- proclaimed “caliphate”. (Photo by Bulent Kilic/AFP Photo)

A man watches a wave hit a rock pool at Curl Curl beach as large swell hits the East Coast of Australia on June 6, 2016 in Sydney, Australia. Torrential rain over the weekend saw streets and homes flooded while wind gusts up to 120km per hour brought down trees and powerlines. A king tide has also seen beachside homes evacuated on Sydney's northern beaches as large waves erode the coast. (Photo by Cameron Spencer/Getty Images)

Long row of shiny new Flying Fortresses, part of huge reserves being built up in Britain for D-Day, stands by to be flown to combat units as replacements, May 25, 1944. (Photo by AP Photo)

Some people prepare to catch offerings thrown by Tengger tribe people into the crater of Bromo volcano to in Probolinggo, East Java province, on June 30, 2018, as part of Yadnya Kasada festival which falls on the 14th day of the Kasada month based on the traditional Hindu lunar calendar. (Photo by Juni Kriswanto/AFP Photo)

Ballerinas perform during an ice-cream factory promotional event at an observation floor of the Moscow International Business Centre, also known as “Moskva-City”, in Moscow, Russia October 25, 2018. (Photo by Shamil Zhumatov/Reuters)

“The King”, Johnathon Haddock poses for a portrait with the Garland before the procession during “Castleton Garland Day” on May 29, 2019 in Castleton, England. The first records of Garland day date back to the 1700's and though it's true origins are not fully understood it is believed to be an ancient fertility rite with Celtic connections. (Photo by Dan Kitwood/Getty Images)