What are these clouds? [Lee clouds]


New Member
Hi everyone, first post - I have been quite fascinated with the sky recently and it's been good finding somewhere with real facts and explanations. Like a lot of people I never took much interest in the sky until a Facebook friend started posting scare-mongering about planes spraying us! I'd of course seen persistent trails but never looked at them with suspicion. Well, every cloud has a silver lining (haw) and actually I've found it interesting learning about clouds, weather and even naming them.

Sorry if ones like these have been posted, but I'd be interested to know what they're called and how they work - are they natural or contrail based? Thanks!

around 9am

around 9.30am

around 10am

Something tells me I won't be able to work on my tan today!
Last edited by a moderator:

Mick West

Staff member
They don't look at all contrail based - there's no evidence of contrails in any of the photos.

They look like altocumulus or cirrocumulus with a strong wind component. If you took a time-lapse of the sky there you'd see the clouds constantly reforming in the same spot and streaming towards you. Possibly related to the peak you see there - a lenticular effect.

Here's something similar


New Member
Hey thanks very much - yes there's some quite high mountains behind the town here. I hadn't seen this effect before though, but as I said I didn't use to pay much attention. I've been looking at Lenticular cloud and they definitely look like the ones. Thanks, keep up the good work, this is a really good site :)