Right. Because that was the power to change the weather. Not the power to summon a magical storm that shoots bolts of lightning at people.
You aren't actually manipulating the weather here. You're creating the storm out of nothing. You can't do a take-it-back shout.
Yes, of course, but in the same way you use your magical abilities in the Shivering Isles to change the weather, you use your voice to invoke a storm.
The power of the voice in Skyrim is just as 'magical' as using a spell is on Oblivion,
In oblivion's case you could create a storm with seemingly no clouds for miles so you could argue you are technically 'crating a storm out of nothing.'
Of course it didn't create lightning bolts that deliberately seeks out your foes to harm them, but it's food for thought.
Even though I still see no way for people to use such a "high level shout" on an enclosed space, and even if we are able I'm willing to bet it will looks quite hilarious :celebration: .
In the comical sense, http://3.bp.blogspot.com/_SCfwBkF65oY/SUGDxZeWUwI/AAAAAAAAHRQ/X-M4MPMbBwI/s400/Blago+cloud+over+head.jpg =].