Sydney is in for some "pretty miserable" weather in coming days as a complex low off the coast brings strong wind gusts and the chance of localised heavy falls, meteorologists say.

The low pressure system will probably be too far offshore to fit into a classic east coast low but "still has the potential to produce nasty rainfall", Stephen Stefanac, a duty forecaster at the Bureau of Meteorology, said.

The bureau later pared back its forecast for rain and is now predicting 1-4 millimetres on Tuesday for the city and 8-20 millimetres on Wednesday.

Just how far the rain falls inland from the coast is uncertain, with models suggesting a "fine line" could mean the difference between some heavy showers or not getting much rain at all, Mr Stefanac said.