I mentioned a couple of weeks ago that a couple of big systems could be in the offing in the first week of october due to the record cold temps in Antarctica.
The first one arrives on Friday just in time for the AFL Grand Final on Saturday.
Here is the latest satellite photo.
Notice the colours are black over the country, thats the very warm air, and you can see the cloudy part near Perth being the colder air.
To give you some idea of the air mass differential, check this out.
The colour red indicates the warm air mass, the blue is the very cold air mass moving up from the SW.
You are looking at a 15-20 degree difference between the 2 air masses, creating an enormous, volatile set up.
Because of the large pressure gradient it will create strong winds, rain, storms, local hail and snow down to low levels.
If we see a system like this in 4 weeks time we will have floods across a fair part of inland Australia, its lucky the air inland is still relatively dry.