Hi Escoba! Maybe I've been visiting www.worth1000.com for too long. I'd expect something like this on there, but here - it just looks wrong! Where did you find the picture?
I hesitate to say "ph*t*sh*p" but this has to be a composite. The storm on the left has the sun above as it's in shadow - but if the sun's above the clouds, how can you get the double rainbow? I'm willing to believe a reasonable explanation, but have to say I'm a bit sceptic. No offence meant.