Please even out JB and FDS special effects
I believe that the effects are actually the same size, but Jormag’s Breath’s “outer flames” are much dimmer/fainter, and therefore do not display well.
http://wiki.guildwars2.com/wiki/Jormag%27s_Breath
If you enlarge the third image, you CAN see that parts of the background wall are tinted blue because you are looking at them through the outer flames. But that shading is about the only indication of the visual effect’s true length.
So, the only real fix needed is to brighten the outer flames of Jormag’s Breath, not to match the core flames, but enough to make it visible.