The Volcano.

[Starlord]

I don't think it's limited to Gridania, just that letter is focused on Gridania and The Black Shroud. We have the lot's of rain in all zones and NPC's popping up and casting things in Ul'dah and such, that leads me to believe that it could encompass everything.

Yes I noticed that as well even Mor Dhona is Experiencing Rain, I dont think Mor Dhona nor Thanalan are known for Rain type Weather... hmmm. You dont think... Leviathan!!!