Okay well Aang is master of air bending, if she throws a tornado at him all he has to do is send wind blowing in the opposite direction and cancel it out. Or he could send wind with a higher or lower pressure which will mess with her control. Things like rain, ice, fog, etc. can all be controlled by Aang as well. We all agree that Storm can't control earth and fire, well Aang can do everything she can and more. Please don't ignore the fact he can tap into any of his past lives and use their technique. Aang won't kill but he can definitely subdue her. I wonder what would happen if he used that technique he used on Ozai(it took away his bending) would have some sort of effect on Storm?
Edit: forgot to say that I am not buying into the whole "Storm controls it he can't manipulate it" I think if they are both trying to control something like the wind will come to a battle of wills, and Aang takes the case there. I'll explain why if anyone cares to know why. Even if he can't manipulate it first mean he can't counter with some of the ways I mentioned in my OP.
Umm no Aang doesn't have control over the weather. Fire and Earth are useless againt Storm. Storm is a mutant so that techique you mentioned wouldn't work. You have yet to tell me what will Aang do when Storm starts to do category 5 hurricanes, tornados, tidal waves, and more all combined which she is capable of doing. Storm has complete control over wind so know he won't mess with her control. Methos already explained why Aang can't redirect actual lightening from the sky. Its not gone be a battle of wills because Aang doesn't have control over weather like Storm.
If Aang uses lightening then Storm easily sends it right back at him, if Aang uses water then Storm will make it evaporate, If Aang uses air then Storm will make the air attacks simply disappear, and more just to give you examples.