I was just in a route where it was raining and thundering....I thought that was the weather I needed so I turned on max repel and biked around the grass. Five repels later all I had fought were two audinos by accident. Eventually it stopped storming. WTF happened? Why didn't Thundurus show? Should I have been in TALL grass instead --- Shelton undoubtedly wants Cena's championship belt. And Cena undoubtedly wants Shelton's black heritage.- looseiver
Also, you're not absolutely guaranteed to encounter Thundurus. If you have two or so regular encounters, chances are it would indeed decide to move to a different area. Just go to one of the area's entrances, and exit/re-enter until it starts raining heavily, again. --- Currently ignoring: Real Life
What caught my attention is that you were BIKING in the area where Thundurus was supposed to show up. Like all other roaming legendaries I've heard of in these games, if you bike through their areas while they're around, they move elsewhere. You have to bike to the closest gate; then WALK through their area in order to encounter them. Give that a try and see if you encounter Thundurus afterward.
Official Cresselia of B/W2 and X/Y Boards; Official Darkrai of PMD: Gates to Infinity Board When will there be an official Cresselia event?
Nothing wrong really, maybe the level of your active pokemon at the top of your list was too high, have you tried to use max repel with a poke below 40 (around 34-39) and put at the top pokemon and run around the grass. --- I Have Returned!! Who am I? That is for you to find out.