Newest observations

Contact information

Ursa Astronomical Association
Kopernikuksentie 1
00130 Helsinki

Ursa Astronomical Association

Other special clouds - 15.3.2016 at 18.50 Kempele Observation number 49533

Visibility IV / V

Jarmo Leskinen, Ursa (Pohjois-Suomi)

Shortly after sunset, a meandering cloud appeared. Does this meet the KH cloud criteria?

Additional information
  • Havainto
    • Other special clouds
  • Cloud coverage in the sky
    • Very small area
  • Other special clouds
    • Kelvin-Helmholtz cloud info

      The Kelvin-Helmholtz clouds are among the most exotic apparitions in the cloud world.

      They resemble regular waves in shape, typically several in succession. String wave strings are created at the top of the cloud mass when there are layers of air moving at different speeds in the air.

      If there is moisture in one layer of air, it may rise into waves in another layer of air moving at different speeds. There is Kelvin-Helmholtz instability between the air layers at that time, from which the cloud waves are named.

      Waves in lakes and seas are the result of this same instability between layers moving at different speeds. Kelvin-Helmholtz waves can also be seen in the gas circles of Jupiter and Saturn, for example.

      Only clearly wavy cases can be called Kelvin-Helmholtz clouds. It is good to be careful not to confuse them with conventional undulatus clouds. The cloud types can be difficult to identify, especially when viewed from the side.

      In a real Kelvin-Helmholtz cloud, the wave structure is clear. Only well-developed and undisputed Kelvin-Helmholtz clouds are collected to the Sky Watch database.

      Wavy Kelvin-Helmholz clouds. Image Grahamuk / Wikipedia.

      Tom Eklund observed these Kelvin-Helmholtz clouds in Finland.

Comments: 8 pcs
Panu Lahtinen - 15.3.2016 at 19.58 Report this

Onpas hienot kiekurat!

Janne Kari - 15.3.2016 at 19.59 Report this

No nyt lähtee, hyvää settiä!

Jyri Kosonen - 15.3.2016 at 20.03 Report this

Täyttänee with flying colors; keksikääpä joku aiheeseen sopiva sanonta tähän, runosuoneni ei juuri nyt tunnu pulpahtavan.

Jari Luomanen - 15.3.2016 at 20.18 Report this

Jestas sentään, nyt kyllä osui kohdalle!

Jouni Hovi - 15.3.2016 at 20.57 Report this

Hävyttömän hienot! Näin selkeät muodot ovat melkoisen harvassa.

Tero Sipinen - 15.3.2016 at 22.06 Report this


(Jyri: ei minultakaan tuon kummempaa sanaleikkiä irronnut ;)

Juha Ojanperä - 15.3.2016 at 22.31 Report this

Hienot tyylipuhtaat KH:t, kuin suoraan oppikirjasta!

Marko Pekkola - 16.3.2016 at 08.17 Report this

On kyllä hieno. Näyttävyyttä päivitetty ylöspäin ylläpidon puolesta. 

Send a comment

Comments are checked and moderated before publication If you want to contact the observer directly about possibilities to use these images, use the Media -form.



characters left

By sending in this comment I confirm, that I've read and understood the the observation system's privacy policy.