Less welcome, however, could be the heavy rain associated with the cold front, particularly as the system develops into a complex low-pressure system from late Tuesday and intensifies as it moves off the NSW coast from Wednesday.
Were forecasting a band of rain to develop right along that eastern seaboard really from Tasmania to south-east Queensland, Ms Scully said.
As of Sunday, weather models were indicating the most intense rainfall will fall over eastern Victoria and the south-east corner of NSW, bringing the risk of flooding.
The soils are near saturated so that any heavy rainfall that does occur over eastern parts of Victoria and eastern parts of NSW is likely to [bring] increased surface run-off, Ms Scully said.
Weatherzone meteorologist Esteban Abellan said the heavy rain could extend as far north as the Illawarra. We could have [weekly] rainfall totals exceeding 100 millimetres by Friday, he said.
Most of NSW had begun to dry out after the state soaked in its second-wettest March on record to kick off autumn, according to the bureau.
Aprils average rainfall was NSWs eighth-driest on record with less than a quarter of the usual rain, while Mays tallies were about 57 per cent of the average for the 1961-90 period used by the bureau as its benchmark.
Autumn temperatures were moderately cooler than average, coming in at about half a degree below the norm for mean temperatures.
For Sydneys Observatory Hill, rainfall during autumn was just shy of half a metre, or about a quarter above the seasonal average. Overnight temperatures were 0.1 degree below the autumn norm while daytime readings were about 1.3 degrees above average, the data shows.
With Tom Rabe
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