I then confirmed using my planetarium program and the free Occult4 specialised occultation prediction software that we in Singapore would be able to see Jupiter exit an occultation by the Moon at around 3:10am in the early morning of Sun 12 August 2012. However, these two celestial objects would only be about 12 degrees above the eastern horizon at that time. Nevertheless, if it's not cloudy, we would be able to see this event from Singapore.
Jupiter would exit the dark side of the Moon, along with Io, Callisto, Ganymede and Europa (Europa would then be transiting Jupiter, so that would be a double occultation exit). (We would not be able to view the "entry" of Jupiter behind the Moon from Singapore as that would happen just before the Moon rises.)
Here are the exact timings for Singapore (at 1d 18m North, 103d 50m East) taken from Occult4:
Jupiter 3:09:25am (initial exit of Jupiter's disk)
Io 3:08:44am
Europa 3:09:39 (transiting Jupiter)
Callisto 3:12:18am
Ganymede 3:20:15am
(Note: the times would differ when viewed from elsewhere, e.g. from Mersing in Johor, these would occur about a minute earlier.)
A check with my planetarium program shows that it would take about 1.5 minutes for Jupiter to complete the exit.
The Moon would then be a waning crescent, 31% illuminated.
As the exit of Jupiter would take place from the dark (non-lit) side of the Moon, I believe we would see Jupiter and its moons suddenly appear from blackness. (Or perhaps that part of the Moon would be partly lit by Earth shine?) So it would be a case of "now you don't see it, but then you do!".
I've done a quick check and have ascertained that the exit of Jupiter would be visible throughout Johor too (and in fact I think all of Peninsula Malaysia).
So those of us doing a Perseids watch that night would have another sight to look out for too!
Here is the webpage of the free Occult4 software:
http://www.lunar-occultations.com/iota/occult4.htm
And here is a screenshot showing the end of the occultation of Jupiter:
