Dying In The Twilight....

[Weather-history]

I saw the remains of a Cb near the horizon, NNW of my location about 10.20pm

Investigated how far away that cloud could have been. I reckon it was over southern Galloway, some 100 miles away.

[Osbourne One-Nil]

I've often wondered how far away things are in the sky, be it clouds or aircraft. I assumed you had tomake an educated guess on their height and then, taking the curvature of the Earth into account, do some trigonometry, but I guess looking at a radar works just as well for clouds like that.