Australian Weather News

Sunday 20 February 2000

Today's weather extremes

Highest rainfall, 24 hours to 9am

Other high falls in WA:
95.0 Wittenoom
86.6 Bulloo Downs Newman
82.4 Mt Vernon

Other high falls in Qld:
95.6 Richmond Hills Aramac
88.5 Burdekin Falls Dam
83.6 Glendhu Mt Garnet

High falls in SA:
72.0 Loxton Research
70.0 Peebinga
65.4 Cadney Park (Copper Hill, about 130km N of Coober Pedy) SA
65.0 Mt Remarkable NP Mambray Creek SA
61.4 Hawker SA
53.0 Cleve SA

	Above: Surface synoptic situation at 1pm EST Left: Rainfall in the 24 hours to 9 this morning Click on image to enlarge

High moisture levels through much of inland Australia continued to produce heavy rain and storms in the WA Pilbara, Central Australia and inland Qld, with heavy falls spreading into eastern SA and western NSW and Vic today. The rain through central northern Australia continues to be produced by areas of convergence into the monsoonal trough, but the incursion of heavy falls into SA this morning and later today into western NSW and Vic were due to a frontal trough system which developed over eastern SA as a slow-moving upper feature moved into the area.

The situation at 500hPa, or about 18,000 feet, is shown at right for the period from 11pm EST Saturday to 11am Tuesday in 12-hour intervals. The white lines show the upper trough, and the green lines the temperature. The red/orange area shows relative vorticity, or the spin being imparted to the air by the trough. The upmotion generated by this middle-level trough caused pressures to fall around the SA/ Vic/ NSW border area during the day, and convergence of unusually moist air into the low triggered exceptionally widespread, heavy falls. The slow movement of the system extended the heavy falls over several days until the upper support decayed.

During the morning, an area of heavy rain with a few embedded thunderstorms gave falls of 25 to 70mm to Adelaide, the Murray Valley, Central North and northwest towards Oodnadatta. From the Flinders Ranges to around Oodnadatta this fell on already sodden ground and again closed roads in the area. Over two metres of floodwater covered some roads in the Hawker/ Leigh Creek/ Wilpena Pound area. Hawker recorded 57mm between 3pm yesterday and 6 this morning, while Yunta, 130km SE, recorded 43mm in 6 hours to 9am. Heavy rain fell in Adelaide around midnight, with 34mm recorded at the airport between 9pm and 3am, but intensified farther east in the Murray Valley, where Loxton recorded 69mm and Renmark PO 34mm in 3 hours to 9am, and Mildura 35mm in 3 hours to midday. By late afternoon, heavy rain was falling the length of the NSW/ Vic/ SA border country with widespread storms activity. (see news for 21/2/00)

Remarkable rainfall continued across the continent from the WA Pilbara (see news for 19/2/00) to central western Qld. Storms, which dumped 104mm on Yulara NT between 3 and 9am, with 84.6mm falling in just two hours to 6.30am, must have made Uluru an impressive sight at dawn. Heavy falls were recorded farther east in the Finke River basin, closing the Stuart Highway south of Alice Springs again, with 1.5m of water reported over the road. Meanwhile, widespread falls between 50 and 100mm were recorded through Queensland's Central West, where between 150 and 400mm has fallen over the past week and minor to moderate flooding is occurring in the Diamantina and Georgina Rivers. 

Monsoonal squall lines off the Pilbara Coast in northwestern WA produced the rare spectacle of 7 funnel clouds or waterspouts in succession today. They were observed mid-afternoon from Point Sampson, 35km east of Karratha, and at one point three funnels and one waterspout (i.e. touching the ocean) were visible simultaneously.

Highest & Lowest Temps

Greatest variations from normal

Wind gust:
Mt Wellington Tas: 111km/h at 2.30am

Flood peak:
Paroo River at Caiwarro Qld: 1.64m at 9pm with minor flooding.

• Times stated are the clock time in force in the relevant state or territory

• Stories, including those in the archives, are as new and corrected information becomes available, with updates underlined

• Australian Weather News gratefully acknowledges the Bureau of Meteorology as the collector and main source of meteorological data in Australia, along with the thousands of observers who record the weather and rainfall daily. I also thank Don White and the many contributors to the Aussie Weather mailing list who routinely provide much appreciated information. 500hPa chart courtesy Mike Fiorino at  PCMDI.