Perth and Western Australia's southwest face possible severe thunderstorms from Thursday afternoon, with the Bureau of Meteorology forecasting a 100 per cent chance of rain, falls of 15 to 40 millimetres and storms that could bring damaging winds and flash flooding.
The Bureau's Perth forecast, issued at 8.05am local time, puts thunderstorms in the afternoon and evening, "possibly severe with damaging winds and heavy rain which may lead to flash flooding". Bunbury's storm window arrived earlier, through the morning and early afternoon, with the same warning text and the same expected totals.
The warnings current in the late morning, eastern time, were marine: a gale warning for the Leeuwin Coast and strong wind warnings for Perth Local Waters and the Geraldton, Lancelin, Perth, Bunbury Geographe and Albany coasts. An initial flood watch covers the Moore and Hill river catchments, including the town of Moora, where the Bureau says moderate falls could bring flooding. An update is due by midday, WA time. No severe thunderstorm warning had been issued by Thursday morning.
The rain does not clear quickly. Friday's Perth forecast holds a 100 per cent chance of rain with 7 to 25 millimetres and a possible afternoon storm, easing to showers on Saturday.
On the other side of the country, the New South Wales North Coast keeps its showers but has so far avoided a bigger event. Weatherzone had flagged the potential for a multi-day deluge earlier in the week; the Bureau's Thursday town forecasts run well below those numbers, with Lismore given a 95 per cent chance of rain and 4 to 40 millimetres for the rest of Thursday, 10 to 50 millimetres on Friday, and Grafton just 1 to 10 millimetres. No flood watch or flood warning is current for any North Coast river.
The coastal factor to watch in NSW is the tide. Thursday night's high is the peak of the coming week: 2.05 metres at Sydney's Fort Denison at 9.53pm, 2.08 metres at Newcastle, and 1.91 metres at Ballina and Yamba around 10pm, easing each night afterwards. A strong wind warning covers six coastal zones from the Byron Coast to the Illawarra, and the Bureau's Grafton forecast notes hazardous surf developing by Saturday.
In Lismore, where the Wilsons River reached its record 14.37 metres in the 2022 flood, the State Emergency Service had issued no operational statements on this week's rain by Thursday morning.
The Bureau's flood watch advice for WA is unchanged: "Don't drive, walk, swim or play in floodwater because it is dangerous." Its next Northern Rivers district forecast is due at 4.30pm, eastern time, and the WA warnings page carries the current storm status through the afternoon.
