How to reach Plane of Storms
The zone in for Plane of Storms can be found in western Plane of Tranquility - along the pathway that leads out into the ocean. The first large round area of this pathway has a small mountain on it; surrounded by what appears to be an electrical storm of sorts. This mountain is shown in the picture above.
You'll need to click on the "stormy" portion of this area in order to zone into Plane of Storms. If you need more assistance with finding this location use my map below for guidance, the area marked in blue with the arrow pointing to it is where you'll find the mountain.
As with most of the zones added in PoP, how to zone out isn't exactly clear either. In the eastern portion of Plane of Storms you'll find a cave with a tree growing in the back of it (seen in my screen shot below). You'll want to click on this tree to zone out.