Nacreous clouds, sometimes called mother-of-pearl clouds, are rare but once seen are never forgotten. That is, until now. The upper layers of air are moving at higher speeds and will often scoop the top of the cloud layer into these wave-like rolling structures. Part I: Wave Clouds. Fallstreak holes can grow as large as 50km in just one hour. Rare Wave-Like Clouds Over Virginia Mountain Look Like Van Gogh’s Famous ‘Starry Night’ The phenomenon’s known as Kelvin-Helmholtz waves, wherein specific atmospheric conditions create clouds that appear in wave-like patterns in the sky. However, once rain starts falling, it causes a downdraft of cool, dense air. Kelvin-Helmholtz Wave Clouds This is a rare type of cloud that resembles ocean waves in the sky. As the rain or snow evaporates away, it cools the surrounding air while increasing its humidity, until finally conditions are ripe for rain to pour. Kelvin–Helmholtz cloud formations, named after Lord Kelvin and Hermann von Helmholtz, are extremely rare. Often seen bulging from the anvil of a severe thunderstorm or from the ragged clouds in a storm's wake, they usually indicate that the worst weather has passed. Worthington, R. M. "Lenticular wave cloud above the convective boundary layer of the Rocky Mountains," Weather 57(2002):87–90. 1 month ago. The resulting instability causes the breaking wave formation, both in the ocean and the air. They consist of dark, chaotic waves that seem to swirl and tumble haphazardly across the sky. In 2008, Gavin Pretor-Pinney of the Cloud Appreciation Society proposed a new type of cloud. These clouds rarely form on windy and unstable days, but when conditions are just right, the natural phenomenon, known as Kelvin-Helmholtz Waves, occurs. facebook; twitter ... “Wave clouds form in a stable atmosphere where the cloud itself isn’t able to develop into a vertical state because it … Rare Wave-Like Clouds Over Virginia Mountain Look Like Van Gogh's Famous 'Starry Night' The phenomenon's known as Kelvin-Helmholtz waves, wherein specific atmospheric conditions create clouds that appear in wave-like patterns in the sky. This rare cloud looks like breaking ocean waves. A rare formation of clouds wowed onlookers at Virginia's Smith Mountain Lake on Tuesday.. They typically form when something forces a mass of air upward. "The base of these clouds is often above 16,500 feet (5,029 meters), as this is where the difference in wind speed in the atmosphere tends to be greatest," adds weather forecaster and former BBC Weatherman, Liam Dutton. SkyTrak 13 Meteorologist Sean Ash says they're a "somewhat rare type of wave clouds." In a supercell, vertical wind shear creates huge horizontal tubes of spinning air. Whether this happens depends on the saturation of the air. Named for the French "nacré", meaning "mother of pearl", nacreous clouds form close to the poles in the extreme cold of winter. These clouds look like ocean waves, and can be a sign of turbulence in the sky. Most group members said they had never seen such an incredible phenomenon before – but there was a reason the rare waves had formed in the clouds. A mountain range can form a series of long wave clouds, but if the speed bump is more isolated, like a single mountain, the result can be oval-shaped clouds that look like UFOs,” explained physicist Patrick Chuang for Wired.com. ©Cherie Ude, shown with permission. As a result, the cloud puffs downwards. These rare clouds, sometimes called mother-of-pearl clouds, are 15 – 25km (9 -16 miles) high in the stratosphere and well above tropospheric clouds. These turbulent atmospheric waves are a sign that the air is extremely unstable. These clouds look like ocean waves, and can be a sign of turbulence in the sky. (Photo Credit: Ken Jones) KDKA meteorologist Ray Petelin says these are Kelvin-Helmholtz clouds, “a very rare cloud pattern that is caused by velocity shear.” After wind blows up and over a barrier, like a mountain, the air continues flowing through the atmosphere in a wavelike pattern. 3 November 2020. Supercells can produce treacherous winds, tennis-ball-sized hailstones and flash floods. Stock Footage of Asperitas Wave Clouds are Rare Indeed. Journal of the Atmospheric Sciences: Vol. As the crystals fall back down, they change from ice to water vapour. Author: Tim Buckley The Kelvin-Helmholtz cloud is named after the scientist who studied them. This is a list of what I believe to be the top 10 rarest cloud formations. A rare wave cloud formation captured on the brink of sunset in the Bay of Plenty has been described as "magic". No particular order in how ‘rare’ they are though. Kelvin-Helmholtz wave clouds are formed when there is … These rare clouds were spotted over southern Michigan Wednesday evening. 63, No. This sinks and flows out of the base of the cloud, smothering the updraft and starving the storm of energy. ONE of the world’s most spectacular clouds made a dramatic entrance for passengers on an … Despite their temperature, these supercooled droplets remain liquid due to a lack of "seed" particles for ice to grow on. The sky had an ocean wave look to it for a time yesterday. In the descending part of the wave, those clouds will evaporate due to adiabaticheating, leading to the characteristic clouded and clear ban… They are relatively easy to study, because they are quite consistent. But it only lasts a few minutes before dispersing without a trace. Rare disc-shaped clouds caught on camera by motorist Extraordinary lens shapes are exceptionally rare lenticular clouds and are also known as wave clouds The clouds are known as Kelvin-Helmholtz instability waves and are named after the scientists who studied the physics behind them. on. Lidiya. Lenticular clouds form when the airflow streaming over the mountain is both stable and humid. On rare occasions, they may also occur with cumulus clouds. As physicists William Kelvin and Hermann von Helmholtz discovered, the difference in the speeds and densities of these fluids creates a shearing force where they meet, producing undulations in the boundary between the two. KDKA viewer Ken Jones captured a photo of rare wave-shaped clouds that he saw over the Turnpike on the way to Philadelphia. Fallstreak holes can grow as large as 50km in just one hour. Lenticular clouds are eerie because they seem to hover in place, even in a steady wind. Named for their smooth, lentil-like appearance, altocumulus lenticularis clouds (pictured above) are believed to be one of the most common explanations for UFO sightings. Wave clouds got their name because they look like waves. Some, like lenticulars and wave clouds, tend to only be seen in the lee of mountain ranges. The atmospheric internal waves that form wave clouds are created as stable air flows over a raised land feature such as a mountain range, and can form either directly above or in the lee of the feature. 3160–3185, "Cloud Crystals - Columns & Plates - Atmospheric Optics", https://en.wikipedia.org/w/index.php?title=Wave_cloud&oldid=994008655, Creative Commons Attribution-ShareAlike License, This page was last edited on 13 December 2020, at 17:52. Advertisement Clouds that look more like breaking ocean waves created a dramatic scene in the western Virginia sky on Tuesday evening. There are a number of theories about how the clouds develop. The rare wave-shaped clouds, known as Kelvin-Helmholtz instability waves, were spotted and photographed by Amy Christie Hunter, who later shared the picture on Facebook. A rare formation of clouds wowed onlookers at Virginia's Smith Mountain Lake on Tuesday.. The photo shared on social media captured clouds that look like ocean waves in the sky. Despite their ominous appearance, they tend to dissipate without turning into storms themselves. If the speed difference is just right, the tops of the denser ripples can roll up, surge forwards, and tip over in a series of vortices, just like a breaking ocean wave. As a result, these storms typically dissipate within about 30 minutes of starting. They are some of the highest and rarest clouds on Earth, but these iridescent specimens are both beauty and beast. As the humid air bubbles up into cooler parts of the atmosphere, the moisture condenses, transforming fluffy cotton-wool clouds into a massive, lumbering rain cloud. (CNN) — A rare formation of clouds wowed onlookers at Virginia's Smith Mountain Lake on Tuesday. The ripples form when humid air at the far-flung edges of the storm system pushes past clear, cool air high in the sky. All tornadoes are associated with supercells, although not all supercells produce tornadoes. Amy Christie Hunter spotted the wave-shaped clouds on … The atmospheric internal waves that form wave clouds are created as stable air flows over a raised land feature such as a mountain range, and can form either directly above or in the lee of the feature. They look like a sky full of floating jellyfish, their dangling tendrils being swept away by the wind. Nacreous clouds accelerate the chemical reactions that convert benign chlorofluorocarbons (CFCs) into ozone-destroying chlorine. This became known as Kelvin-Helmholtz Instability (KHI). ... Quite often, these clouds will form with cirrus, altocumulus, stratocumulus, and stratus clouds. The observatory explained that the rare phenomenon, called a KH-lenticular or Kelvin-Helmholtz wave cloud, "forms when a large increase in winds occurs over a small vertical distance within a cloud." Lenticular clouds are eerie because they seem to hover in place. Rare wave clouds rolled through the sky over Smith Mountain Lake in Virginia on Tuesday: ‘It was so amazing’ ... Kelvin-Helmholtz wave clouds don’t last long. Not an official cloud classification but rather a "supplementary feature", virga form when rain or snow begins to fall but evaporates or sublimates in mid-air. Pretor-Pinney proposed the name asperatus, meaning "roughened" or "agitated". It was not until 1802 that Luke Howard started classifying clouds into groups. Cade Hughes said he and his wife were relaxing on … As a result, they are being analyzed to increase our understanding of how these upper-level ice clouds influence the Earth's radiation budget. As the crystals fall back down, they change from ice to water vapour. Wave cloud structure ranges from smooth and simple, to jumbled phases occurring randomly. Another rare glimpse of Kelvin-Helmholtz wave clouds over Fort Collins. They have iridescent colours but are higher and much rarer than ordinary iridescent clouds. A rare wave cloud formation captured on the brink of sunset in the Bay of Plenty has been described as "magic". Rare Wave-Like Clouds Crest Over Pa. Turnpike November 26, 2019 at 1:22 pm Filed Under: Clouds , Local TV , Pennsylvania Turnpike , Philadelphia , Ray Petelin , turnpike WTHR Meteorologist Sean Ash says "Tsunami clouds" may be a nickname for the clouds but they are actually called the Kelvin-Helmholtz cloud and are pretty rare. The prettiest jellyfish skies occur mostly with high clouds that tend to form individual cloudlets, like altocumulus and cirrocumulus. Understanding this can improve climate models. They form from small amounts of moisture in the air ahead of approaching weather fronts. High altitude can be another contributing factor, simply because there is more air for the rain to fall through before reaching the ground. [1] Often, ice crystals can be found downwind of the waves. Rare wave-shaped clouds spotted in Virginia A photo of some wave-shaped clouds is making the rounds on social media and it may have you wondering if it's legit. As you might imagine, weather conditions have to be just right for these wave-like clouds to appear. the water droplets are racing through the cloud, View image of A nacreous cloud at sunset (Credit: Pekka Parviainen/SPL), View image of Asperitas clouds (Credit: Laurent Laveder/SPL), View image of Kelvin-Helmholtz waves (Credit: Brad Lundgren), View image of A supercell thunderstorm over Nebraska (Credit: Roger Hill/SPL), View image of Cirrocumulus clouds forming a mackerel sky (Credit: Pekka Parviainen/SPL), View image of Mammatus clouds over Nebraska (Credit: Mike Hollingshead/SPL), View image of Clouds with virga, over the desert in Utah (Credit: Frank Zullo/SPL), associated with many different kinds of cloud, View image of A fallstreak hole over California (Credit: Kimberly Kradel/Alamy), surrounding droplets spontaneously freeze. Multi-level mountain wave clouds form when the moisture in the air above the mountain is located in distinct layers, and vertical mixing is inhibited. January 2008. Our language of clouds dates back to 1802, when amateur scientist and earnest sky watcher Luke Howard delivered a lecture tntitled "On the Modifications of Clouds". They all hinge on sharp differences in temperature and humidity between the cloud and the underlying air, and pronounced wind shear at the boundary. A rare series of 5 unique images showing the formation of Kelvin-Helmholtz clouds from a base of altocumulus over South-East England in August 2018. As it flows upwards and cools, the moisture in the air condenses to form clouds at the crests of the standing wave. Baker, B. [1], It is possible that simple convection from mountain summits can also form wave clouds. Evaporation of the cloud causes a downdraft on the edges that erodes the cloud, forming a roll. Amy Hunter snapped this photo of incredible wave-shaped clouds that were spotted in Virginia. That rule of thumb became all-too relevant recently when an unbelievably rare cloud formation known as Kelvin-Helmholtz instability waves appeared in the sky over Smith Mountain Lake. This is a list of what I believe to be the top 10 rarest cloud formations. A rare formation of clouds wowed onlookers at Virginia's Smith Mountain Lake on Tuesday.The photo shared on social media captured clouds that look like ocean waves in the sky. The main mechanism for ice formation is homogeneous nucleation. This occurs as the convection forces a wave or lenticular wave cloud into the more stable air above. Their destructive might is second only to hurricanes. These super rare wave-shaped clouds were photographed yesterday in Erie. The clouds are called Kelvin Helmholtz clouds… Clouds resembling breaking ocean waves appeared in the skies above Breckenridge, Colorado, in the final week of October.. In June 2015, the name – slightly modified to its noun form, asperitas – was officially accepted into the World Meteorological Organisation's International Cloud Atlas, the reference system used by meteorologists across the globe. As the air spills over the other side, the pull of gravity causes it to overshoot a little before resurging back up. Also called mother of pearl clouds or sun dogs, these rare clouds are rarely seen, but once you do, you most definitely won’t forget them. On rare occasions, they may also occur with cumulus clouds. They are wave clouds and their undulating sheet-like forms reveal the winds and waves of the stratosphere. The observatory explained that the rare phenomenon, called a KH-lenticular or Kelvin-Helmholtz wave cloud, "forms when a large increase in winds … On Earth, but these iridescent specimens are both beauty and beast tendrils... 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