Go over where the water elementals are. There should be a tower behind them (near the floating rocky bridge), and the scroll is tucked away behind that tower. The guide below shows a photo of where the scroll is plus if you look carefully, he shows you where he is on the map.
Try looking at the tower adjacent to where you see the storm mobs. It's on the outside to the right of the tower, just before you cross the floating stone bridge.
Alia Misthaven
