I really like clouds. This evening I noticed the sky was covered in streamers of stripy, iron grey cloud. According to my Cloud Collector’s Handbook by the lovely Gavin Pretor-Pinney, this is altostratus undulatus radiatus. Here is a photo I took from my house:
Figuring that the sky was going to get interesting, I took a walk up the hill to get a better viewpoint. The sky kept changing. Here it looks like it’s trying to explode, with cloud streamers reaching up to the heavens (well it did to me when I was standing in the field).
The next photo is the cloudspotter’s pride and joy – the Kelvin-Helmholtz cloud. This is where the cloud briefly forms into breaking waves and is worth 55 points in the Handbook. Apparently some clever physics is involved, hence the name. The waves only lasted about 30 seconds then they sank back into the top of the cloud.
OK, so that one was probably for the cloud nerds. Here is something to make you smile. It has the rather catchy name of circumzenithal arc but it is really a cloud smile – an upside down rainbow with no rain in sight. I saw this one a couple of days ago. They appear right above your head, which is a shame as most people never know the sky has smiled down on them.
That’s probably enough cloudspotting for now. If you are a cloud nerd too, check out the Cloud Appreciation Society website – it has more clouds than you could ever wish for!