Kiwiconehead sums up the situation at major Australian airports however it should be said that the systems are airline specific and I think relate to their OH&S responsibilities. I believe Qantas operates their's centrally from their Sydney Ops Room and it is simply based on what the local BoM weather radar is displaying. If there is lightning within five NM strobe lights start flashing all over the apron and the staff down tools until the lights stop. I think Virgin Blue has something similar but I stress this is only on those airlines ramps. There are no airport or ATC restrictions, and as someone points out earlier, for weather issues, only pilots close airports (by declining approaches or take offs)not ATC. (As it should be) I assume any paperwork that Ranklein is searching for would be in airline documents.