The 1999 Sydney hailstorm was the costliest natural disaster in Australian history at the time as measured by insured damage. The storm developed south of Sydney, New South Wales, on the afternoon of 14 April 1999 and struck the city's central business district and its eastern suburbs later that evening. It dropped an estimated 500,000 tonnes of hailstones on Sydney and its suburbs. The insured damage bill was roughly A$1.7 billion, with the total bill (including uninsured damage) estimated to be around $2.3 billion. Lightning claimed one life, and the storm caused approximately 50 injuries. The storm was classified as a supercell following further analysis of its erratic nature and extreme attributes. The time of year and general conditions in the region were not seen as conducive for an extreme storm cell to form, and the Bureau of Meteorology was repeatedly surprised by its changes in direction, its duration, and the severity of the hail. (Full article...)