Someone placed two stones(Stormy weather and sunset) near me. I used my [N.U.K.U.L.A.R. Target Painter] and then 1 min later used hearthstone. The two buffs from the stone didn't go away even though I was no longer near the stones.
As you can see I teleported to other places to test the effect. I removed stormy weather buff by myself as it was hard to tell whether it was sunrise or sunset. Some zones didn't show the weather effect, but others did. Buffs seem to survive the relog. I haven't tested if they get removed whenever your character dies. At any rate, if you are able to reproduce it, enjoy!
http://i.imgur.com/tKiwQtu.jpg
tKiwQtu.jpg
Same place in Nagrand, from different character.
http://i.imgur.com/5GiD3Tg.png
As you can see I teleported to other places to test the effect. I removed stormy weather buff by myself as it was hard to tell whether it was sunrise or sunset. Some zones didn't show the weather effect, but others did. Buffs seem to survive the relog. I haven't tested if they get removed whenever your character dies. At any rate, if you are able to reproduce it, enjoy!
http://i.imgur.com/tKiwQtu.jpg
tKiwQtu.jpg
Same place in Nagrand, from different character.
http://i.imgur.com/5GiD3Tg.png