There are some in one of the temple squares in Straits of Devastation. Not entirely sure which one though, but each Column there seems to have a different type of elemental guarding them.
I realize this is an old question, but I was looking for these same mobs today, and found them in Malchor’s Leap, around the Cathedral of Eternal Radiance.
Many elemental types can be found here, including Ice, Air, Fire, Earth.
The attached picture shows the area (highlighted in red) where level 78 Embers (Fire Elementals) are found. There are approximately 8 spawns, and one veteran. Also in the same indicated area are two Risen Catapults, so bringing a friend is recommended.
