LAX/SFO to SYD will almost always hit some pretty rough air. There have been more than a few incidents of severe turbulence on this route.

Worst I had was UA LAX-MEL (remember that route?), where the F/As were sitting down for about 3-4 hours in the middle of the flight.

I have flown into/out of Singapore about 25 times and have never experienced any bad turbulence. Once to SIN we flew right near a major tropical cyclone around the top of Australia. Expecting severe turbulence the captain turned on the seat belt and ordered the F/As seated for about 2 hours - amazingly there was not a bump. Whenever anyone stood up while the seat belt sign was on the F/As said over the PA "Due to turbulent weather all passengers must remain seated". They must have made this announcement 10 times. Pity the folks who really were bustin'. After the seat belt signed was turned back on there was certainly a major queue to use the bathroom.

MD