This site has a nice sheet of Song of Storms:
http://cruiseelroy.net/2008/04/ocarina-music-1/
The harmony is pretty simple though, the first four chords (Dm, Em, F and Em) can be thought of being in D Dorian. Then, you have Bb, F, Bb, A for the next four chords, and that is D minor. Essentially, the song uses Bb for a few chords instead of B, it isn't a huge alteration.