A BIG purple monster in the shape of possible 400mm rainfall totals is lurking off the Queensland coast.
That same major weather system is set to deliver 100mm on Queensland tropical north coast during the eight days, according to the Bureau of Meteorology's latest modelling.
An east coast low is also expected to impact on the coast of southern NSW.
However, it is the next four days that will see much of Queensland receive a drenching of 15mm to 50mm, with heavier falls possible in some areas.
That rain is expected to extend right through from the Northern Territory through to south east Queensland.
BoM said on Friday morning a trough over north western and central Queensland was deepening in response to an upper trough over central Australia. This was likely to dissipate by Sunday.
The official forecaster said an upper trough over central Australia wiould drift east over the next few days, extending a cloud band over much of the state before weakening over the weekend.
BoM says a second upper trough would then intensify over central Queensland from late Sunday, resulting in more rain over eastern Queensland.
That trough was expected to clear Queensland by Wednesday.
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