Bind it to a hotkey and spam it while you fly over his spawn locations. Exciting, huh?/cleartarget
/target Gondria
/stopmacro [noexists]
/run RaidNotice_AddMessage[RaidBossEmoteFrame,"YOUR MESSAGE HERE",ChatTypeInfo["RAID_WARNING"])
/script PlaySoundFile("Sound\\interface\\RaidWarning.wav")

Basically it attempts to target him, and if it finds him you get the raid warning noise and a big message of your choice across your screen, and if it doesn't find him it won't do anything.
As for spawn locations, I'm not even sure if they're all known yet, but you will be able to find an up-to-date map with Google, or BRK probably has one on his site.