Models really wet on the update. EC got 100mm here, CMC around 50mm, GFS about 25mm, ACCESS around 50mm. Ensembles across the models are really consistent also.
Looks to me like a statewide event, and the north will do well as a record humid airmass surges south. The latest GFS has precipitable water values of 50mm for Melbourne Monday morning. The March record is 47mm so you are talking a system bringing down tropical air and fast.
Of course, could wiggle across the models and some spots will miss out, but this is one of the best set of progs I've seen in a long time. One key with this system is it is large and not developing that rapidly which tends to mean better predictability.
Maybe time for its own thread it it's still there in the models come morning