This spectacular cloud stretched for some 10 miles, from north Portsmouth to Chichester, and parallel to the coast about 3 miles from the open sea (the water in the photo is at the head of Emsworth creek). It persisted for the best part of an hour.
It's not a sea breeze front, as a force 5 or 6 was blowing parallel to the coast, and is probably just an example of a 'cloud street'. But if anyone can come up with reasons for its unusually well defined nature and persistence, I'd be interested.
In the end it slipped away and declined inland - this was taken half an hour after the others and the remnants are on the left.
War does not determine who is right, only who is left - Bertrand Russell
Chichester 12m asl