Mate
A TAF is a valid forecast for 5nm ONLY around an aerodrome.
Your general weather forecast for Brisbane (you showed later) is a general non aviation forecast for the greater Brisbane area. ie a lot bigger area than the 5nm around the airport.
So if the Met forecasters don't think the storm will get within 5nm, the TAF won't even mention it.
So in theory there could be stationary TS all around the airfield and in theory the TAF does not have to mention it.
That is why an AREA forecast goes hand in hand with a TAF, so you can get the big picture. A SIGWX chart completes the forecast.
Gliderboy