Showers and thunderstorms skirting the New South Wales and Queensland coasts are threatening to deliver some heavy falls.
In NSW some showers and storms are riding on a southerly wind change which is moving up the coast, and others are forming further north, where relatively warm and moist air is combining with a low pressure trough.
In Queensland southeasterly winds are pumping moisture into a weak, but persistent trough just offshore, causing showers over a long stretch.
Between now and next weekend these systems will lead to heavy falls on the coast with help from another surge of southerly winds late in the week. Widespread 20-to-50 millimetres is likely between about Sydney and Cooktown with potential for near 100mm in places.
The wettest area is most likely to be on the northern tropical QLD coast, in the Innisfail area, where moisture levels and instability will be highest and falls will penetrate to the hinterland. Otherwise, the coasts most exposed to the southerly winds should be quite wet – south-facing coasts. These may include Anna Bay, Forster, Ballina, Double Island Point, Yeppoon and Mackay.
Each location can expect showers on most days this week, making it worthwhile using weatherzone.com.au for rainfall probabilities and amounts each day.