Houghy,
Tamworth is a little better than Port Mc. Newcastle is worse than Sydney in the current model run. But there are many many more GFS model runs due to be published before Wednesday each will become progressively more accurate.
At present Moree is looking good and NW of Goondiwindi excellent if you want to travel.
You can do your own time series predictions for your location on the NOAA Air Resources Laboratory web site. Note that the GFS model has limited spatial resolution±0.5 degrees.
http://www.arl.noaa.gov/
Just plug in your Lat long and select the meteogram/ total cloud cover option.
Andrew Cools Skippy Sky site publishes the same info from the same model using a 2D map format. When displaying information, you have to make compromises. Andrew's web app is a very slick, user friendly, graphical representation of the GFS model predictions. However Andrew's site only gives 12hr time increments. This isn't a criticism, Andrew funds Skippy Sky out of his own pocket. The data downloads from the model publications cost him a bomb. He can't afford to increase the temporal resolution.
The ARL site is not user friendly, gives finer time increments but gives a plot of a selected meteorological parameter against time. I use a combination of both when evaluating weather (and whether ;-).
images below from left are for Newcastle, Port Macquarrie, Tamworth, Moree and a bit NW of Goondiwindi.
Joe