Torrential
rain breaks dry spell in SW WAStrong
winds cause damage north of PerthHeavy
rain and storms along the coast from Sydney to Rockhampton 
17May01Strong, squally winds ahead of the trough caused damage around Kalbarri, 120km north of Geraldton. Sheds were torn apart and 20 power poles flattened in what the press described as tornadic winds, though no thunderstorms were reported by any Bureau stations in WA during the morning. Power was cut for much of the morning to towns north, east and south of Geraldton.
Following on from yesterday afternoon's downpour, central Sydney received another dowsing this morning, with 40mm falling in 3 hours to 9am to produce a 24 hour to 9am total of 94mm. A succession of heavy showers moving northwards off the Illawarra coast crossed the coast into southern Sydney between 9 last night and 9 this morning, bringing 24-hour totals of 50 to 90mm to southern coastal suburbs, the CBD and inner northern parts. On the Central Coast, Norah Head reported 70mm for the 9 hours to 9am. The bands of heavy showers developed along local wind convergence lines in a strong SSE airstream squeezed between a 1029hPa high over Victoria and a 999hPa low near New Zealand.
A marked upper circulation together with cold upper air increased both instability and convergence over eastern NSW today resulting in continuing heavy showers and thunderstorms along the coast from around Sydney to Rockhampton, Queensland. A thunderstorm at Wollongbar, 10km east of Lismore, during the early evening produced downdrafts strong enough to unroof a service station and damage a nearby two-storey block of flats. Hail up to 15cm deep fell in the storm, during which trees were blown onto powerlines. Alongside the Bruxner Highway between Alstonville and Wollongbar, drifts of hail up to 30cm deep accumulated, with stones up to 2.5cm in diameter observed. A detailed report is available in Storm News.
Storms accompanied by heavy rain and some hail also developed along a weak troughline that moved across Brisbane and the Gold Coast before dawn, then redeveloped between Gympie and Rockhampton late afternoon and evening.