confusion NLC with cirrus clouds

[menno]

In the late evening I observed NLC clouds in the WNW to NNW from 22:10 till 22:50 UTC. Location: centre of the Netherlands. After that I went to bed, because I needed the sleep....
However, I had some doubts that it were just normal cirrus clouds lit by an almost fool moon. I doubted because I saw the clouds also in a direction (290 degrees), where I had never seen them before. Also the appearance of the clouds was much like that of ordinary cirrus clouds (I reported them as type IIb on the form).
But, the clouds were hardly moving and sounding data of nearby stations around that time showed that there was a moderate flow from the NW at cirrus-levels. So I identified the clouds as NLC, although I'm not 100% sure.

Are there other members of this forum who have experienced this confusion before? And, when in doubt, are there other methods to distinguish NLC from cirrus clouds?

[tmcewan]

I have even observed cirrus illuminated by the twilight arch - worth looking out for that too. I think the best advice is to examine the 'cloud' with binoculars. Binoculars reveal more detail and sometimes a fibrous/textured quality to NLC (even in veils), but not with cirrus. Cirrus tends to have a light grey or milky white appearance too, whereas NLC is more bluish. If I'm not 100 percent sure I report a 'possible'.

[martinastro]

It sounds like what you did see was NLC going by your description. Cirrus can be tricky but as Tom said binoculars usually reveal the presence of NLC. This is was what I used last night to detect NLC through normal cloud before it cleared. If you see structure then it is NLC. I have noticed that another way of telling is with a digital camera. By playing with the exposure (a little under exposed) you can see the distinctive glow on the LCD screen once you preview the image. Hope this helps.

Good luck.

[menno]

Thanks for your comments, Tom and Martinastro!
In the future I will use a binocular more often and will try playing with my DSLR when in doubt.