Spectators Balcony (Spotters Corner)If you're not a professional pilot but want to discuss issues about the job, this is the best place to loiter. You won't be moved on by 'security' and there'll be plenty of experts to answer any questions.
Some very big and active CB's in the London area on 10th late afternoon, moving West to affect Bristol and Cardiff in the evening, might have something to do with it.