Bump this thread to the top.
Classic example of "scudsucking" this week of image of tornado after the London event that was then sold on to the Press. Fooled many people, and I myself have been fooled in the past by these fakes.
All the more reason to be wary of the "Perfect Funnel". The London tornado probably would have been rain-wrapped and therefore impossible to see, as is the case with most UK tornadoes.
The only nadoes that can usually be seen here in the UK are those that form under developing, but as yet non precipitating Cu or Cb. These are generaly weak, and often do not reach the ground.
Thinking about the weather pattern before, during and after a tornado may go some way to determining if an image is real or fake.
Nigel B.