Summary of Significant Severe Thunderstorm Events in NSW - 1970/1979

1978

1 March 1978
Severe thunderstorm North Coast

Severe storms on the North Coast injured 2 people, left 15 people homeless and caused estimated damages of approximately $42 million.

10 February 1978
Severe thunderstorms Newcastle to Wollongong

Severe storms affected Sydney, Newcastle and Wollongong on 10th and 11th. There was extensive damage to buildings and 8 people were injured. Power was lost to many homes. Wind gusts reached 141 km/h at Newcastle on 11th, the highest wind gust on record in February. A tornado accompanied one thunderstorm in the Drummoyne/Hunters Hill area of Sydney, lifting the entire roof off one home and damaging many others. Total damage bill was $44 million.

1976

9 November 1976
Severe thunderstorm Western Sydney with hail

A severe hailstorm blanketed a huge area of Western Sydney and some other parts of NSW, causing extensive damage to homes and vehicles. Hail was up to golf ball size and wind gusts reached 96 km/h. The total damage bill was $131 million with 10 people injured.

1975

9 March 1975
Severe storms Sydney area with flash flooding

Severe flash flooding resulted in heavy damage at Gosford, Sydney and the Illawarra region. Total damage bill was $63 million.

1974

20-23 April 1974
Sydney-Blue Mountains storms and flash flooding

Severe flash flooding causing heavy damage (and 1 death) in Sydney's western suburbs and the Blue Mountains following about 200mm of rain in three days. A total of 225mm was recorded at Mount Wilson (Central Tablelands). Total damage bill was $98 million.

1971

26 January 1971
7 people die in Canberra Woden Valley Storm

A highly efficient supercell thunderstorm caused flash flooding and 7 deaths due to drowning and injuries. Widespread flooding occurred in Woden Valley, south-east of the city, which rapidly filled the concrete-lined creek that ran beside the Woden Valley freeway.

At the time of the storm, the freeway was packed with commuters heading home. As the deluge began, the traffic halted with culverts at one end of the valley becoming blocked with debris. The backup of water sent a flash flood surging onto the freeway with a wall of water engulfing more than a dozen cars, sweeping them away in the torrent. Roads and stormwater systems were also extensively damaged.

At a subsequent coroner's inquiry into the drownings, engineers described how the valley's stormwater system had been designed to accommodate a "100-year-storm". Its impact may have been a storm of this magnitude, but its effect was exacerbated by excessive runoff from urbanised land which, a decade previously, had been grassland and woodland. Rainfalls up to 100mm in 1 hour were recorded by private rain gauges in the suburb of Farrer and Torrens. The total damage bill was $9 million.