The current main source for closure information is the Tibet Tourism Bureau. (Which all agencies liase with). The only problem with this source is that the TTB (or TTA depending on which label it has on the day) does not make the decisions.......much higher levels of government actually make the closure decisions and the TTB just has to react accordingly. So TTB is trying to placate the tour operators but they haven't actually been told of any final decisions.....they never do until the last minute. So TTB is just the messenger.....
The govt. does this so they can then respond to international pressure and proudly announce that Tibet is not closed to foreigners. Its a deliberate govt. policy to leave the decision to the last minute. The usual official media announcement is something like "we had to close Tibet due to safety concerns or weather issues at short notice...."........yeah right!!
There is no place to read about the planned closures in greater detail as they have not been officially announced yet and won't be until relatively short notice. Subsequently we're going to hear lots of rumours about closure dates but we won't hear "official" word until the govt. tells the TTB - the TTB calls in the agencies in Lhasa for a meeting to let them know the bad news - then the agencies will be able to pass on this info through email and web etc.
Its time for a very zen approach to travel in Tibet this summer........