Can Anyone identify this formation?

[Richard Tighe]

This photograph was taken in Manley, New South Wales, on the evening of March 24, 2015. Weather conditions were calm and it was about 20 degrees C. I have never before seen anything like this on the underside of what I assume is a stratus layer.

[Howard Brown]

In short, no, Richard, and I have never seen anything like it either. Assuming it was not raining, I guess you can rule out Nimbostratus. I guess someone will say asperatus

I don’t think you can rule out Stratocumulus, particularly at the top, and the bottom where it might be lenticularis? There might be undulatus in between?

ICA Vol II, pages 28 and 29, show Stratus nebulosus. It mentions things like the height of the cloud base not being uniform, being thinner in parts e.g. near your horizon; differences in optical thickness may reveal undulatus.

Great picture. Many thanks.

[Catherine Kearns]

As mentioned, it is evening but I don’t know the clouds approximate height.
Your cloud is so beautiful.
I get the impression the cloud has captured the sunlight and shows as a lovely Noctilucent cloud.
Your location is in the northern climes where these clouds readily show themselves.
This is my guess

How grand it must have felt to see this lovely display. Thanks for sharing
Member 37993
Cate

[marc de cleyn]

i am a starter, studying the art of clouds. and writing the english language. what does the “ICA Vol II, pages 28 and 29″mean.
marc

[Howard Brown]

Hallo, Marc, and welcome. ICA = International Cloud Atlas, Manual on the Observation of Clouds and Other Meteors, World Meteorological Organization. Volume I, Revised edition 1975, is a technical manual; Volume II 1987 is 212 pages of pictures – page 28 Stratus nebulosus undulatus, page 29 Stratus nebulosus.

I use these books a lot, but to be honest I don’t think many others do. They are available on-line:

ICA Vol I & II

We learnt on the old forum that the ICA will be updated one day by WMO.

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