Nice pic dude and i have to agree things are looking pretty weird up there i got a few big showers nearby but no thunder from them, yet
Edit: Just heard some thunder! and a rain that came out of nowear!
Here try this one in exmouth acording to nw radar its just about to hit the rain and you can see the rain getting closer to the camera from the sea! http://www.exmouthcam.co.uk/webcam/ It just looks white out to sea which is prob rain as about 10 mins ago you could see to the other side of the coast