August 2006

Cloud of the Month for August 2006

August 2006

Cloud of the Month for August 2006

‘Surf’s Up’ at 24,000ft over Georgia, US.

The classic 1964 surfing documentary, The Endless Summer, followed the adventures of three surfers traveling from Malibu to Ghana, via Nigeria, Australia, New Zealand, Tahiti, and Hawaii in search of the perfect wave. Cloudspotters can experience their own perfect wave too, without ever having to leave home – all they need is a lot of patience. The only down side to the ultimate aerial breaker, is that it has the particularly un-hip name of the ‘Kelvin-Helmholtz cloud’.

The breaking waveforms of ‘Kelv-Helmz’ (as they aren’t known) are the result of shearing winds up at cloud level. A particular type of turbulence can develop in a layer of Cirrus cloud, which happens to form below an inversion* between air currents of differing speeds and/or directions. Sea waves break as their bases are slowed down upon reaching shallow water and their crests surge ahead. Cloud waves break in the same way: when their crests are pushed ahead of their troughs by the difference in air currents.

Though spotter-dudes won’t have to cross the world to see this formation, those in search of the perfect Kelvin-Helmholtz will have to wait a while. This most beautiful and transient of formations may appear over most regions of the world but it only ever does so on the rarest of occasions.

*An inversion is a region where air temperatures change with altitude in such a way as to act as an invisible ‘ceiling’ that stops clouds from rising through it.

Photograph © Brian Wong

30 Comments
  • chieko

    June 16, 2011 at 7:48 pm

    I have been lucky enough to have seen these clouds this year in between Santa Fe and Albuquerque, NM at dusk. I watched them form and was completely fascinated by them as I drove south on the highway. Unfortunately, I had no camera with me but they are ingrained in my memory!

  • pony express

    October 5, 2011 at 8:07 pm

    Today I saw them, the imfomiss kelvin-helmholtz clouds comming home from work. Unfortunately they were gone within a few minutes, so I did’nt have time to take pictures.Where were these clouds seen, Brampton,Ontario,Canada

  • Jo L

    October 21, 2011 at 11:35 am

    I saw these clouds over the Atlantic Ocean on my birthday this year, 13 October. I was surfing at Saunton, North Devon, UK. My friends were a long way down the beach and were too busy watching the waves on the ocean to see these amazing formations in the sky! I had to make some new friends to share them with;)
    What a wonderful birthday gift, perfect waves twice over!

  • SOettle

    November 12, 2011 at 4:18 pm

    I saw some over Jacksonville, Illinois today. Sadly, my camera wasn’t with me. :( They were pretty awesome!

  • […] From the Cloud Appreciation Society… The breaking waveforms of Kelvin-Helmholtz clouds are the result of shearing winds up at cloud level. A particular type of turbulence can develop in a layer of cirrus cloud, which happens to form below an inversion between air currents of differing speeds and/or directions. Sea waves break as their bases are slowed down upon reaching shallow water and their crests surge ahead. Cloud waves break in the same way: when their crests are pushed ahead of their troughs by the difference in air currents. To see more pictures from Alabama follow this link and scroll down […]

  • Vemos olas por todos lados…

    December 19, 2011 at 12:56 am

    […] Nubes: http://cloudappreciationsociety.org/the-kelvin-helmholtz-wave-cloud/ […]

  • Elizabeth Taylor

    December 20, 2011 at 6:40 am

    These were seen Dec 16,2011 in Birmingham,Ala on Utube home vid called …Tsunami wave cloud over Birmingham,Ala

  • […] More information cloudappreciationsociety.org […]

  • ana

    December 20, 2011 at 2:27 pm

    sorry to tell you but these clouds are not good sign… Earth changes are violent and upheaval at our doorstep
    may look “nice” but, as sign, not at all…

  • […] UPDATE: Let’s send this TO James Spann… “The breaking waveforms of ‘Kelv-Helmz’ (as they aren’t known) are the result of shearing winds up at cloud level. A particular type […]

  • […] “The breaking waveforms of ‘Kelv-Helmz’ (as they aren’t known) are the result of shearing winds up at cloud level. A particular type of turbulence can develop in a layer of Cirrus cloud, which happens to form below an inversion* between air currents of differing speeds and/or directions. Sea waves break as their bases are slowed down upon reaching shallow water and their crests surge ahead. Cloud waves break in the same way: when their crests are pushed ahead of their troughs by the difference in air currents.” http://cloudappreciationsociety.org/the-kelvin-helmholtz-wave-cloud/ […]

  • […] known as the Kelvin-Helmholtz wave clouds according to The Cloud Appreciation Society, these “are the result of shearing winds up at cloud level. A particular type of turbulence […]

  • Osborne Ink » Tsunami Clouds

    December 26, 2011 at 10:22 pm

    […] way: when their crests are pushed ahead of their troughs by the difference in air currents.” (Link) Video […]

  • Weak Winter (so far) « Greg's Weather Blog

    December 29, 2011 at 6:08 am

    […] how fluid the atmosphere is, and how it relates to the liquid you may be taking a sip of now! The Cloud Apreciation Society labels these iconic wave clouds as nothing short of a water wave in the air: The breaking waveforms […]

  • Mary

    January 2, 2012 at 4:02 am

    Ana, I’m interested in hearing & learning more about your statement, I believe you are right! Please email me with your facts, thoughts, and anything at mekickitgirl@gmail.com Thank you

  • J-Dawn

    February 4, 2012 at 3:40 pm

    I saw those the other day and was fortunate enough to have my camera with me. http://www.flickr.com/photos/jdawn82/6809560611/ Only got one or two good shots before they leveled off.

  • Ian Uzzell

    March 19, 2012 at 8:27 am

    I saw some yesterday whilst driving. I passed my camera to my wife who took some photos before they dissipated. I will post on the photo section later

  • Jen Fountain

    March 24, 2012 at 10:02 pm

    We had some here in Honesdale, PA today. I was only able to take two photos – very cool!

  • Warren Arbuckle

    November 13, 2012 at 9:53 pm

    I saw my first Kelvin-Helmholtz cloud formation on 30/10/2012, 5.20pm above Margate, Tasmania. They were formed atop of a Lenticular cloud, so even rarer to see. I managed to scramble for my camera , but only got a couple of shots as they were collapsing. Very special moment :-)

  • giddens

    December 4, 2012 at 2:13 pm

    I saw these fabulous clouds in the morning at a B&B in Lynton,Devon in October this year.I took several photos but don’t know how to get them from my camera to the website!

  • Savitri Simpson

    December 27, 2012 at 8:14 pm

    I saw them on the day before 12-21-12. You can imagine what I thought? Never saw them before, but nice to know what they are. I got a pretty good photo with a cell phone (this is in No. Cal). Should I send the photo somewhere?

  • Anonymous

    February 6, 2013 at 9:27 pm

    nice ion

  • Anonymous

    February 6, 2013 at 9:27 pm

    sorry nice info

  • qwertydog

    February 13, 2013 at 9:12 pm

    Saw these hidden within stratocumulus clouds one day.

  • New Scientist | Airscrews

    August 7, 2013 at 4:54 pm

    […] Such waves in clouds are extremely short-lived, usually dissipating within a few minutes – and so often go unseen. I have seen them twice. On one of those occasions, just the wave crests were visible for less than a minute. […]

  • David Geddes

    November 14, 2013 at 10:12 pm

    Sunday 10 Nov 2013. Observed a beautiful display of KHI in the sky west of Rum and Skye (Scotland) amidst a setting sun. Pics on web site per URL given in the album ‘View from Meall Gorm’.

  • David Geddes

    November 14, 2013 at 10:15 pm

    Direct link to web album image https://picasaweb.google.com/101567632500778470634/TheSceneryFromMeallGormApplecross#5944718788365326770 The cloud display was present for at least 2 hours. One large commercial jet going west threaded the cloud spirals.

  • #cotd | Aurora borealis

    November 15, 2013 at 12:03 am

    […] skies for the elusive circumzenithal arc (which looks like an upside-down rainbow on a sunny day), Kelvin-Helmholtz waves (cloud waves), radiatus (which fan out from the horizon), and even the common rainbow. (How do I not […]

  • Alicia

    December 13, 2013 at 12:24 pm

    Just saw some during the sun rise in DC this AM. They were pink!

  • Bean thinking » From a Caravan to the Grecian

    September 17, 2014 at 9:59 am

    […] “Kelvin Helmholtz clouds”, a beautiful but very rare cloud type, for an example click here. Helmholtz realised that the formation of these clouds required that two layers of air rubbed […]

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